Sandbox Reserved 951: Difference between revisions
From Proteopedia
Jump to navigationJump to search
No edit summary |
No edit summary |
||
| Line 38: | Line 38: | ||
We find a signal motif in luciferase which is <scene name='60/604470/Atp_binding_signal_motif/1'>[STG]-[STG]-G-[ST]-[ST]-[TSE]-[GS]-x-[PALIVM]-K</scene> where some residues like lysine are always conserved. This pattern enables ATP binding thanks to hydrogen bonds between residues and phosphates of ATP. There is another pattern : <scene name='60/604470/Adenosine_ring_binding/1'>[YFW]-[GASW]-x-[TSA]-E</scene> which takes a particular conformation because of hydrogen bonds between residues and maintain the adenosin ring of ATP.<ref name =''fifth''>PMID:8805533</ref>, <ref>[http://www.photobiology.info/ Photobiology]</ref> | We find a signal motif in luciferase which is <scene name='60/604470/Atp_binding_signal_motif/1'>[STG]-[STG]-G-[ST]-[ST]-[TSE]-[GS]-x-[PALIVM]-K</scene> where some residues like lysine are always conserved. This pattern enables ATP binding thanks to hydrogen bonds between residues and phosphates of ATP. There is another pattern : <scene name='60/604470/Adenosine_ring_binding/1'>[YFW]-[GASW]-x-[TSA]-E</scene> which takes a particular conformation because of hydrogen bonds between residues and maintain the adenosin ring of ATP.<ref name =''fifth''>PMID:8805533</ref>, <ref>[http://www.photobiology.info/ Photobiology]</ref> | ||
=====Interaction with luciferin===== | =====Interaction with luciferin===== | ||
Luciferase holds the luciferin with the specific residues <scene name='60/604470/Residues_helding_luciferin/1'>arginin 218, phenylalanin 247, serin 347 and adenin 348</scene>, still with hydrogen bounds. | Luciferase holds the luciferin with the specific residues <scene name='60/604470/Residues_helding_luciferin/1'>arginin 218, phenylalanin 247, serin 347 and adenin 348</scene>, still with hydrogen bounds. Those bindings make the carboxylate oxygen of luciferin points toward the α phosphate of ATP, so the oxygen is well-positionned to attack the α phosphate. This promotes the luciferin-AMP formation.<ref name =''sixth''>PMID:8805533</ref>, <ref>[http://www.photobiology.info/ Photobiology]</ref> | ||
=====Interaction with fatty acids===== | =====Interaction with fatty acids===== | ||
Fatty acids are highly similar to luciferin. Therefore, luciferase can use the luciferin binding site to bind fatty acids. That is why they can be used as substrates by luciferase and then, very high similar reaction as for luciferin occurs. | Fatty acids are highly similar to luciferin. Therefore, luciferase can use the luciferin binding site to bind fatty acids. That is why they can be used as substrates by luciferase and then, very high similar reaction as for luciferin occurs. | ||
| Line 49: | Line 49: | ||
== Evolution == | == Evolution == | ||
The number of proteins related to luciferase is growing exponentially. They are a lot of enzymes | The number of proteins related to luciferase is growing exponentially. They are a lot of different enzymes involved in a lot of mechanisms such as biosynthesis of siderophores, of antibiotics, of fatty acid :coenzyme A ligase, and so on... | ||
All the coenzyme A ligase show a very high level of similarity : indeed, each of these | All the coenzyme A ligase show a very high level of similarity : indeed, each of these enzymes related to luciferase catalyze the adenylation of a carboxylic acid substrate using ATP-Mg2+ and then, the ligation of the activated carboxylic acid with an acceptor. | ||
That is why luciferase is more and more considered as coming from a common ancestor involved in this kind of reaction and the light production would only be a side effect of the reaction.<ref>PMID:19859663</ref> | That is why luciferase is more and more considered as coming from a common ancestor involved in this kind of reaction and the light production would only be a side effect of the reaction.<ref>PMID:19859663</ref> | ||
