SecA - Revision history

Michal Harel at 11:58, 14 November 2023

2023-11-14T11:58:02Z

← Older revision		Revision as of 11:58, 14 November 2023
Line 47:		Line 47:
	**[[3dl8]] – BsSecA + AaSecY + AaSecE + AaSecG – ''Aquifex aeolicus''<br />		**[[3dl8]] – BsSecA + AaSecY + AaSecE + AaSecG – ''Aquifex aeolicus''<br />
	**[[6itc]] – BsSecA + SecY + SecE + nanobody + GFP + peptide – Cryo EM<br />		**[[6itc]] – BsSecA + SecY + SecE + nanobody + GFP + peptide – Cryo EM<br />
			**[[7xha]], [[7xhb]] – BsSecA + GtSecY + GtSecE + translocating polypeptide + ADP – ''Geoacillus thermodenitrificans'' - Cryo EM<br />
	**[[3din]] - TmSecA + TmSecY + TmSecE + TmSecG<br />		**[[3din]] - TmSecA + TmSecY + TmSecE + TmSecG<br />
	**[[1ozb]] - SecA + SecB – Haemophilus influenzae<br />		**[[1ozb]] - SecA + SecB – Haemophilus influenzae<br />

Michal Harel at 08:00, 15 March 2022

2022-03-15T08:00:41Z

← Older revision		Revision as of 08:00, 15 March 2022
Line 37:		Line 37:
	**[[1nl3]] – MtSecA 1 – ''Mycobacterium tuberculosis''<br />		**[[1nl3]] – MtSecA 1 – ''Mycobacterium tuberculosis''<br />
	**[[4uaq]] – MtSecA 2<br />		**[[4uaq]] – MtSecA 2<br />
	**[[6sxh]] – ~~SecA~~ 2 – ''Peptoclostridium difficile''<br />		**[[6sxh]] – PdSecA 2 – ''Peptoclostridium difficile''<br />


Line 57:		Line 57:
	**[[1nkt]] - MtSecA 1 + ADP <BR />		**[[1nkt]] - MtSecA 1 + ADP <BR />
	**[[4ys0]] - TmSecA + ADP <BR />		**[[4ys0]] - TmSecA + ADP <BR />
			**[[6t4h]] – PdSecA 2 + ATP derivative<br />
	}}		}}
	=References=		=References=
	<references/>		<references/>
	[[Category:Topic Page]]		[[Category:Topic Page]]

Michal Harel at 07:54, 15 March 2022

2022-03-15T07:54:27Z

← Older revision		Revision as of 07:54, 15 March 2022
Line 1:		Line 1:
	<StructureSection load='3jv2' size='350' side='right' scene='' caption='Dimer of monomeric SecA complex with peptide (pink and yellow), ADP and Mg+2 ion (green), [[3jv2]]' pspeed='8'>		<StructureSection load='3jv2' size='350' side='right' scene='' caption='Dimer of monomeric SecA complex with peptide (pink and yellow), ADP and Mg+2 ion (green), [[3jv2]]' pspeed='8'>
	=Introduction=		=Introduction=
	The [http://www.nature.com/nature/journal/v455/n7215/full/nature07335.html SecA] ATPase '''SecA''' or '''~~protein~~ translocase subunit SecA''' drives the post-translational translocation of proteins through the SecY channel in the bacterial inner membrane. SecA is a dimer that can dissociate into monomers under certain conditions. Many bacterial proteins are transported post-translationally across the inner membrane by the Sec machinery, which consists of two essential components (1-4). One is the SecY complex, which forms a conserved heterotrimeric protein-conducting channel in the inner membrane.<ref name=journal1>PMID:15618215</ref> The other is SecA, a cytoplasmic ATPase, which "pushes" substrate polypeptide chains through the SecY channel.<ref name=journal1/> . For additional details see [[SecA PBD motions]].		The [http://www.nature.com/nature/journal/v455/n7215/full/nature07335.html SecA] ATPase '''SecA''' or '''preprotein translocase subunit SecA''' drives the post-translational translocation of proteins through the SecY channel in the bacterial inner membrane. SecA is a dimer that can dissociate into monomers under certain conditions. Many bacterial proteins are transported post-translationally across the inner membrane by the Sec machinery, which consists of two essential components (1-4). One is the SecY complex, which forms a conserved heterotrimeric protein-conducting channel in the inner membrane.<ref name=journal1>PMID:15618215</ref> The other is SecA, a cytoplasmic ATPase, which "pushes" substrate polypeptide chains through the SecY channel.<ref name=journal1/> . For additional details see [[SecA PBD motions]].

	=Structure=		=Structure=

Michal Harel at 08:50, 1 November 2020

2020-11-01T08:50:13Z

← Older revision		Revision as of 08:50, 1 November 2020
Line 37:		Line 37:
	**[[1nl3]] – MtSecA 1 – ''Mycobacterium tuberculosis''<br />		**[[1nl3]] – MtSecA 1 – ''Mycobacterium tuberculosis''<br />
	**[[4uaq]] – MtSecA 2<br />		**[[4uaq]] – MtSecA 2<br />
			**[[6sxh]] – SecA 2 – ''Peptoclostridium difficile''<br />


	*SecA complexes		*SecA complexes

Michal Harel at 09:27, 21 January 2020

2020-01-21T09:27:12Z

Michal Harel at 09:17, 21 January 2020

2020-01-21T09:17:26Z

← Older revision		Revision as of 09:17, 21 January 2020
Line 1:		Line 1:
	<StructureSection load='3jv2' size='350' side='right' scene='' caption='Dimer of monomeric SecA complex with peptide (pink and yellow), ADP and Mg+2 ion (green), [[3jv2]]' pspeed='8'>		<StructureSection load='3jv2' size='350' side='right' scene='' caption='Dimer of monomeric SecA complex with peptide (pink and yellow), ADP and Mg+2 ion (green), [[3jv2]]' pspeed='8'>
	=Introduction=		=Introduction=
	The [http://www.nature.com/nature/journal/v455/n7215/full/nature07335.html SecA] ATPase '''SecA''' drives the post-translational translocation of proteins through the SecY channel in the bacterial inner membrane. SecA is a dimer that can dissociate into monomers under certain conditions. Many bacterial proteins are transported post-translationally across the inner membrane by the Sec machinery, which consists of two essential components (1-4). One is the SecY complex, which forms a conserved heterotrimeric protein-conducting channel in the inner membrane.<ref name=journal1>PMID:15618215</ref> The other is SecA, a cytoplasmic ATPase, which "pushes" substrate polypeptide chains through the SecY channel.<ref name=journal1/> . For additional details see [[SecA PBD motions]].		The [http://www.nature.com/nature/journal/v455/n7215/full/nature07335.html SecA] ATPase '''SecA''' or '''protein translocase subunit SecA''' drives the post-translational translocation of proteins through the SecY channel in the bacterial inner membrane. SecA is a dimer that can dissociate into monomers under certain conditions. Many bacterial proteins are transported post-translationally across the inner membrane by the Sec machinery, which consists of two essential components (1-4). One is the SecY complex, which forms a conserved heterotrimeric protein-conducting channel in the inner membrane.<ref name=journal1>PMID:15618215</ref> The other is SecA, a cytoplasmic ATPase, which "pushes" substrate polypeptide chains through the SecY channel.<ref name=journal1/> . For additional details see [[SecA PBD motions]].

	=Structure=		=Structure=

Michal Harel at 18:22, 17 September 2018

2018-09-17T18:22:24Z

← Older revision		Revision as of 18:22, 17 September 2018
Line 1:		Line 1:
	<StructureSection load='3jv2' size='~~400~~' side='right' scene='' caption='Dimer of monomeric SecA complex with peptide (pink and yellow), ADP and Mg+2 ion (green), [[3jv2]]' pspeed='8'>		<StructureSection load='3jv2' size='350' side='right' scene='' caption='Dimer of monomeric SecA complex with peptide (pink and yellow), ADP and Mg+2 ion (green), [[3jv2]]' pspeed='8'>
	=Introduction=		=Introduction=
	The [http://www.nature.com/nature/journal/v455/n7215/full/nature07335.html SecA] ATPase '''SecA''' drives the post-translational translocation of proteins through the SecY channel in the bacterial inner membrane. SecA is a dimer that can dissociate into monomers under certain conditions. Many bacterial proteins are transported post-translationally across the inner membrane by the Sec machinery, which consists of two essential components (1-4). One is the SecY complex, which forms a conserved heterotrimeric protein-conducting channel in the inner membrane.<ref name=journal1>PMID:15618215</ref> The other is SecA, a cytoplasmic ATPase, which "pushes" substrate polypeptide chains through the SecY channel.<ref name=journal1/> . For additional details see [[SecA PBD motions]].		The [http://www.nature.com/nature/journal/v455/n7215/full/nature07335.html SecA] ATPase '''SecA''' drives the post-translational translocation of proteins through the SecY channel in the bacterial inner membrane. SecA is a dimer that can dissociate into monomers under certain conditions. Many bacterial proteins are transported post-translationally across the inner membrane by the Sec machinery, which consists of two essential components (1-4). One is the SecY complex, which forms a conserved heterotrimeric protein-conducting channel in the inner membrane.<ref name=journal1>PMID:15618215</ref> The other is SecA, a cytoplasmic ATPase, which "pushes" substrate polypeptide chains through the SecY channel.<ref name=journal1/> . For additional details see [[SecA PBD motions]].

Michal Harel at 18:22, 3 October 2017

2017-10-03T18:22:14Z

← Older revision		Revision as of 18:22, 3 October 2017
Line 35:		Line 35:
	**[[3jux]], [[4ys0]] – TmSecA – ''Thermotoga maritima''<br />		**[[3jux]], [[4ys0]] – TmSecA – ''Thermotoga maritima''<br />
	**[[2ipc]] – SecA – ''Thermus thermophilus''<br />		**[[2ipc]] – SecA – ''Thermus thermophilus''<br />
	**[[1nl3]] – MtSecA – ''Mycobacterium tuberculosis''		**[[1nl3]] – MtSecA 1 – ''Mycobacterium tuberculosis''<br />
			**[[4uaq]] – MtSecA 2<br />

	*SecA complexes		*SecA complexes
Line 41:		Line 42:
	**[[3jv2]] – BsSecA + peptide <br />		**[[3jv2]] – BsSecA + peptide <br />
	**[[1tf2]], [[1m74]] - BsSecA + ADP <BR />		**[[1tf2]], [[1m74]] - BsSecA + ADP <BR />
			**[[5eul]] - BsSecA + SecY + SecE + AYC08<br />
	**[[3dl8]] – BsSecA + AaSecY + AaSecE + AaSecG – ''Aquifex aeolicus''<br />		**[[3dl8]] – BsSecA + AaSecY + AaSecE + AaSecG – ''Aquifex aeolicus''<br />
	**[[3din]] - TmSecA + TmSecY + TmSecE + TmSecG<br />		**[[3din]] - TmSecA + TmSecY + TmSecE + TmSecG<br />
Line 47:		Line 49:
	**[[2fsg]] - EcSecA + ATP <BR />		**[[2fsg]] - EcSecA + ATP <BR />
	**[[2fsi]] - EcSecA + ADP <BR />		**[[2fsi]] - EcSecA + ADP <BR />
			**[[5k9t]] - EcSecA (mutant) + ADP <BR />
	**[[2fsh]] - EcSecA + AMPPNP <BR />		**[[2fsh]] - EcSecA + AMPPNP <BR />
	**[[1nkt]] - MtSecA + ADP <BR />		**[[1nkt]] - MtSecA 1 + ADP <BR />
			**[[4ys0]] - TmSecA + ADP <BR />
	}}		}}
	=References=		=References=
	<references/>		<references/>
	[[Category:Topic Page]]		[[Category:Topic Page]]

Alexander Berchansky at 09:32, 23 May 2017

2017-05-23T09:32:56Z

← Older revision		Revision as of 09:32, 23 May 2017
Line 1:		Line 1:
	<StructureSection load='3jv2' size='400' side='right' scene='' caption='Dimer of monomeric SecA complex with peptide (pink and yellow), ADP and Mg+2 ion (green), [[3jv2]]'>		<StructureSection load='3jv2' size='400' side='right' scene='' caption='Dimer of monomeric SecA complex with peptide (pink and yellow), ADP and Mg+2 ion (green), [[3jv2]]' pspeed='8'>
	=Introduction=		=Introduction=
	The [http://www.nature.com/nature/journal/v455/n7215/full/nature07335.html SecA] ATPase '''SecA''' drives the post-translational translocation of proteins through the SecY channel in the bacterial inner membrane. SecA is a dimer that can dissociate into monomers under certain conditions. Many bacterial proteins are transported post-translationally across the inner membrane by the Sec machinery, which consists of two essential components (1-4). One is the SecY complex, which forms a conserved heterotrimeric protein-conducting channel in the inner membrane.<ref name=journal1>PMID:15618215</ref> The other is SecA, a cytoplasmic ATPase, which "pushes" substrate polypeptide chains through the SecY channel.<ref name=journal1/> . For additional details see [[SecA PBD motions]].		The [http://www.nature.com/nature/journal/v455/n7215/full/nature07335.html SecA] ATPase '''SecA''' drives the post-translational translocation of proteins through the SecY channel in the bacterial inner membrane. SecA is a dimer that can dissociate into monomers under certain conditions. Many bacterial proteins are transported post-translationally across the inner membrane by the Sec machinery, which consists of two essential components (1-4). One is the SecY complex, which forms a conserved heterotrimeric protein-conducting channel in the inner membrane.<ref name=journal1>PMID:15618215</ref> The other is SecA, a cytoplasmic ATPase, which "pushes" substrate polypeptide chains through the SecY channel.<ref name=journal1/> . For additional details see [[SecA PBD motions]].
Line 7:		Line 7:
	Here we report crystal structures of SecA bound in an intermediate state of nucleotide hydrolysis to the SecY channel. The structures suggest mechanisms for how the channel is opened and prepared for the arrival of a translocation substrate, and how SecA moves polypeptides through the channel.		Here we report crystal structures of SecA bound in an intermediate state of nucleotide hydrolysis to the SecY channel. The structures suggest mechanisms for how the channel is opened and prepared for the arrival of a translocation substrate, and how SecA moves polypeptides through the channel.

	Notable finding is that ADP binding to the high-affinity site stabilizes a compact conformation of SecA (ground state) that has low affinity for the SecYEG/membrane<ref name=journal1/>. Click the green link to view the active site of <scene name='~~Sandbox_158~~/~~Scene_1~~/3'>ADP</scene> with surrounding amino acids. This result suggests that following ATP hydrolysis, the ADP-bound SecA undergoes retraction from the translocon to complete one reaction cycle. However, the apo (nucleotide free) form of SecA can also exist in a compact conformation with low affinity for the translocon<ref name=journal1/>. Moreover, ADP release from SecA is stimulated by SecYEG/membrane, raising the question whether SecA retraction from the membrane occurs in the ADP-bound form, the apo form, or both<ref name=journal1/>.		Notable finding is that ADP binding to the high-affinity site stabilizes a compact conformation of SecA (ground state) that has low affinity for the SecYEG/membrane<ref name=journal1/>. Click the green link to view the active site of <scene name='38/382930/Cv/3'>ADP</scene> with surrounding amino acids (Water molecules shown as red spheres). This result suggests that following ATP hydrolysis, the ADP-bound SecA undergoes retraction from the translocon to complete one reaction cycle. However, the apo (nucleotide free) form of SecA can also exist in a compact conformation with low affinity for the translocon<ref name=journal1/>. Moreover, ADP release from SecA is stimulated by SecYEG/membrane, raising the question whether SecA retraction from the membrane occurs in the ADP-bound form, the apo form, or both<ref name=journal1/>.

	==Structure Determination Of SecA-SecY Complexes==		==Structure Determination Of SecA-SecY Complexes==

Alexander Berchansky at 09:05, 23 May 2017

2017-05-23T09:05:50Z

← Older revision		Revision as of 09:05, 23 May 2017
Line 1:		Line 1:
			<StructureSection load='3jv2' size='400' side='right' scene='' caption='Dimer of monomeric SecA complex with peptide (pink and yellow), ADP and Mg+2 ion (green), [[3jv2]]'>
	=Introduction=		=Introduction=
	The [http://www.nature.com/nature/journal/v455/n7215/full/nature07335.html SecA] ATPase '''SecA''' drives the post-translational translocation of proteins through the SecY channel in the bacterial inner membrane. SecA is a dimer that can dissociate into monomers under certain conditions. Many bacterial proteins are transported post-translationally across the inner membrane by the Sec machinery, which consists of two essential components (1-4). One is the SecY complex, which forms a conserved heterotrimeric protein-conducting channel in the inner membrane.<ref name=journal1>PMID:15618215</ref> The other is SecA, a cytoplasmic ATPase, which "pushes" substrate polypeptide chains through the SecY channel.<ref name=journal1/> . For additional details see [[SecA PBD motions]].		The [http://www.nature.com/nature/journal/v455/n7215/full/nature07335.html SecA] ATPase '''SecA''' drives the post-translational translocation of proteins through the SecY channel in the bacterial inner membrane. SecA is a dimer that can dissociate into monomers under certain conditions. Many bacterial proteins are transported post-translationally across the inner membrane by the Sec machinery, which consists of two essential components (1-4). One is the SecY complex, which forms a conserved heterotrimeric protein-conducting channel in the inner membrane.<ref name=journal1>PMID:15618215</ref> The other is SecA, a cytoplasmic ATPase, which "pushes" substrate polypeptide chains through the SecY channel.<ref name=journal1/> . For additional details see [[SecA PBD motions]].


	~~{{STRUCTURE_3jv2\| PDB=3jv2 \| SIZE=400\| SCENE=Sandbox_158/Scene_1/1 \|right\|CAPTION=Dimer of monomeric SecA complex with peptide (pink and yellow), ADP and Mg+2 ion (green), [[3jv2]] }}~~

	=Structure=		=Structure=
Line 23:		Line 21:
	=Expression of the ''Bacillus subtilis'' secA Gene=		=Expression of the ''Bacillus subtilis'' secA Gene=
	In ''Bacillus subtilis'', the secretion of extracellular proteins strongly increases upon transition from exponential growth to the stationary growth phase. It is not known whether the amounts of some or all components of the protein translocation apparatus are concomitantly increased in relation to the increased export activity. In this study, we analyzed the transcriptional organization and temporal expression of the secA gene, encoding a central component of the ''B. subtilis'' preprotein translocase. We found that secA and the downstream gene (prfB) constitute an operon that is transcribed from a vegetative (A-dependent) promoter located upstream of secA. Furthermore, using different independent methods, we found that secA expression occurred mainly in the exponential growth phase, reaching a maximal value almost precisely at the transition from exponential growth to the stationary growth phase. Following to this maximum, the de novo transcription of secA sharply decreased to a low basal level. Since at the time of maximal secA transcription the secretion activity of ''B. subtilis'' strongly increases, our results clearly demonstrate that the expression of at least one of the central components of the ''B. subtilis'' protein export apparatus is adapted to the increased demand for protein secretion. Possible mechanistic consequences are discussed.<ref name=journal3>PMID:9882663</ref>		In ''Bacillus subtilis'', the secretion of extracellular proteins strongly increases upon transition from exponential growth to the stationary growth phase. It is not known whether the amounts of some or all components of the protein translocation apparatus are concomitantly increased in relation to the increased export activity. In this study, we analyzed the transcriptional organization and temporal expression of the secA gene, encoding a central component of the ''B. subtilis'' preprotein translocase. We found that secA and the downstream gene (prfB) constitute an operon that is transcribed from a vegetative (A-dependent) promoter located upstream of secA. Furthermore, using different independent methods, we found that secA expression occurred mainly in the exponential growth phase, reaching a maximal value almost precisely at the transition from exponential growth to the stationary growth phase. Following to this maximum, the de novo transcription of secA sharply decreased to a low basal level. Since at the time of maximal secA transcription the secretion activity of ''B. subtilis'' strongly increases, our results clearly demonstrate that the expression of at least one of the central components of the ''B. subtilis'' protein export apparatus is adapted to the increased demand for protein secretion. Possible mechanistic consequences are discussed.<ref name=journal3>PMID:9882663</ref>
			</StructureSection>
	=3D structures of SecA=		=3D structures of SecA=
	{{REVISIONDAY2}}-{{MONTHNAME\|{{REVISIONMONTH}}}}-{{REVISIONYEAR}}		{{REVISIONDAY2}}-{{MONTHNAME\|{{REVISIONMONTH}}}}-{{REVISIONYEAR}}

← Older revision		Revision as of 09:27, 21 January 2020
Line 31:		Line 31:
	**[[2ibm]], [[1tf5]], [[1m6n]] - BsSecA<br />		**[[2ibm]], [[1tf5]], [[1m6n]] - BsSecA<br />
	**[[3bxz]] - EcSecA (mutant) – ''Escherichia coli''<br />		**[[3bxz]] - EcSecA (mutant) – ''Escherichia coli''<br />
	**[[2fsf]] – EcSecA<br />		**[[2fsf]] , [[6gox]] – EcSecA<br />
	**[[1tm6]], [[1sx0]], [[1sx1]] – EcSecA zinc-binding domain - NMR<br />		**[[1tm6]], [[1sx0]], [[1sx1]] – EcSecA zinc-binding domain - NMR<br />
	**[[3jux]], [[4ys0]] – TmSecA – ''Thermotoga maritima''<br />		**[[3jux]], [[4ys0]] – TmSecA – ''Thermotoga maritima''<br />
Line 44:		Line 44:
	**[[5eul]] - BsSecA + SecY + SecE + AYC08<br />		**[[5eul]] - BsSecA + SecY + SecE + AYC08<br />
	**[[3dl8]] – BsSecA + AaSecY + AaSecE + AaSecG – ''Aquifex aeolicus''<br />		**[[3dl8]] – BsSecA + AaSecY + AaSecE + AaSecG – ''Aquifex aeolicus''<br />
			**[[6itc]] – BsSecA + SecY + SecE + nanobody + GFP + peptide – Cryo EM<br />
	**[[3din]] - TmSecA + TmSecY + TmSecE + TmSecG<br />		**[[3din]] - TmSecA + TmSecY + TmSecE + TmSecG<br />
	**[[1ozb]] - SecA + SecB – Haemophilus influenzae<br />		**[[1ozb]] - SecA + SecB – Haemophilus influenzae<br />
			**[[6s0k]] – EcSecA in ribosome – Cryo EM<br />
	**[[2vda]] – EcSecA + maltoporin signal peptide <br />		**[[2vda]] – EcSecA + maltoporin signal peptide <br />
	**[[2fsg]] - EcSecA + ATP <BR />		**[[2fsg]] - EcSecA + ATP <BR />