1t2o: Difference between revisions

Line 1:

[[Image:1t2o.gif|left|200px]]<br /><applet load="1t2o" size="~~450~~" color="white" frame="true" align="right" spinBox="true"

[[Image:1t2o.gif|left|200px]]<br /><applet load="1t2o" size="350" color="white" frame="true" align="right" spinBox="true"

caption="1t2o, resolution 2.30Å" />

'''Crystal structure of Se-SrtA, C184-Ala'''<br />

==Overview==

The cell wall envelope of staphylococci and other Gram-positive pathogens, is coated with surface proteins that interact with human host tissues., Surface proteins of Staphylococcus aureus are covalently linked to the, cell wall envelope by a mechanism requiring C-terminal sorting signals, with an LPXTG motif. Sortase (SrtA) cleaves surface proteins between the, threonine (T) and the glycine (G) of the LPXTG motif and catalyzes the, formation of an amide bond between threonine at the C-terminal end of, polypeptides and cell wall cross-bridges. The active site architecture and, catalytic mechanism of sortase A has hitherto not been revealed. Here we, present the crystal structures of native SrtA, of an active site mutant of, SrtA, and of the mutant SrtA complexed with its substrate LPETG peptide, and describe the substrate binding pocket of the enzyme. Highly conserved, proline (P) and threonine (T) residues of the LPXTG motif are held in, position by hydrophobic contacts, whereas the glutamic acid residue (E) at, the X position points out into the solvent. The scissile T-G peptide bond, is positioned between the active site Cys(184) and Arg(197) residues and, at a greater distance from the imidazolium side chain of His(120). All, three residues, His(120), Cys(184), and Arg(197), are conserved in sortase, enzymes from Gram-positive bacteria. Comparison of the active sites of S., aureus sortase A and sortase B provides insight into substrate specificity, and suggests a universal sortase-catalyzed mechanism of bacterial surface, protein anchoring in Gram-positive bacteria.

The cell wall envelope of staphylococci and other Gram-positive pathogens is coated with surface proteins that interact with human host tissues. Surface proteins of Staphylococcus aureus are covalently linked to the cell wall envelope by a mechanism requiring C-terminal sorting signals with an LPXTG motif. Sortase (SrtA) cleaves surface proteins between the threonine (T) and the glycine (G) of the LPXTG motif and catalyzes the formation of an amide bond between threonine at the C-terminal end of polypeptides and cell wall cross-bridges. The active site architecture and catalytic mechanism of sortase A has hitherto not been revealed. Here we present the crystal structures of native SrtA, of an active site mutant of SrtA, and of the mutant SrtA complexed with its substrate LPETG peptide and describe the substrate binding pocket of the enzyme. Highly conserved proline (P) and threonine (T) residues of the LPXTG motif are held in position by hydrophobic contacts, whereas the glutamic acid residue (E) at the X position points out into the solvent. The scissile T-G peptide bond is positioned between the active site Cys(184) and Arg(197) residues and at a greater distance from the imidazolium side chain of His(120). All three residues, His(120), Cys(184), and Arg(197), are conserved in sortase enzymes from Gram-positive bacteria. Comparison of the active sites of S. aureus sortase A and sortase B provides insight into substrate specificity and suggests a universal sortase-catalyzed mechanism of bacterial surface protein anchoring in Gram-positive bacteria.

==About this Structure==

1T2O is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://~~ispc~~.weizmann.ac.il/oca-bin/ocashort?id=1T2O OCA].

1T2O is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1T2O OCA].

==Reference==

Line 13:

[[Category: Single protein]]

[[Category: Staphylococcus aureus]]

[[Category: Bice, T.W.]]

[[Category: Bice, T W.]]

[[Category: Narayana, S.V.]]

[[Category: Narayana, S V.]]

[[Category: Schneewind, O.]]

[[Category: Ton-That, H.]]

Line 22:

[[Category: transpeptidase]]

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''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:09:12 2008''

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@@ Line 1: / Line 1: @@
-[[Image:1t2o.gif|left|200px]]<br /><applet load="1t2o" size="450" color="white" frame="true" align="right" spinBox="true"
+[[Image:1t2o.gif|left|200px]]<br /><applet load="1t2o" size="350" color="white" frame="true" align="right" spinBox="true"
 caption="1t2o, resolution 2.30&Aring;" />
 '''Crystal structure of Se-SrtA, C184-Ala'''<br />
 ==Overview==
-The cell wall envelope of staphylococci and other Gram-positive pathogens, is coated with surface proteins that interact with human host tissues., Surface proteins of Staphylococcus aureus are covalently linked to the, cell wall envelope by a mechanism requiring C-terminal sorting signals, with an LPXTG motif. Sortase (SrtA) cleaves surface proteins between the, threonine (T) and the glycine (G) of the LPXTG motif and catalyzes the, formation of an amide bond between threonine at the C-terminal end of, polypeptides and cell wall cross-bridges. The active site architecture and, catalytic mechanism of sortase A has hitherto not been revealed. Here we, present the crystal structures of native SrtA, of an active site mutant of, SrtA, and of the mutant SrtA complexed with its substrate LPETG peptide, and describe the substrate binding pocket of the enzyme. Highly conserved, proline (P) and threonine (T) residues of the LPXTG motif are held in, position by hydrophobic contacts, whereas the glutamic acid residue (E) at, the X position points out into the solvent. The scissile T-G peptide bond, is positioned between the active site Cys(184) and Arg(197) residues and, at a greater distance from the imidazolium side chain of His(120). All, three residues, His(120), Cys(184), and Arg(197), are conserved in sortase, enzymes from Gram-positive bacteria. Comparison of the active sites of S., aureus sortase A and sortase B provides insight into substrate specificity, and suggests a universal sortase-catalyzed mechanism of bacterial surface, protein anchoring in Gram-positive bacteria.
+The cell wall envelope of staphylococci and other Gram-positive pathogens is coated with surface proteins that interact with human host tissues. Surface proteins of Staphylococcus aureus are covalently linked to the cell wall envelope by a mechanism requiring C-terminal sorting signals with an LPXTG motif. Sortase (SrtA) cleaves surface proteins between the threonine (T) and the glycine (G) of the LPXTG motif and catalyzes the formation of an amide bond between threonine at the C-terminal end of polypeptides and cell wall cross-bridges. The active site architecture and catalytic mechanism of sortase A has hitherto not been revealed. Here we present the crystal structures of native SrtA, of an active site mutant of SrtA, and of the mutant SrtA complexed with its substrate LPETG peptide and describe the substrate binding pocket of the enzyme. Highly conserved proline (P) and threonine (T) residues of the LPXTG motif are held in position by hydrophobic contacts, whereas the glutamic acid residue (E) at the X position points out into the solvent. The scissile T-G peptide bond is positioned between the active site Cys(184) and Arg(197) residues and at a greater distance from the imidazolium side chain of His(120). All three residues, His(120), Cys(184), and Arg(197), are conserved in sortase enzymes from Gram-positive bacteria. Comparison of the active sites of S. aureus sortase A and sortase B provides insight into substrate specificity and suggests a universal sortase-catalyzed mechanism of bacterial surface protein anchoring in Gram-positive bacteria.
 ==About this Structure==
-T2O is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1T2O OCA].
+T2O is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Staphylococcus_aureus Staphylococcus aureus]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1T2O OCA].
 ==Reference==
@@ Line 13: / Line 13: @@
 [[Category: Single protein]]
 [[Category: Staphylococcus aureus]]
-[[Category: Bice, T.W.]]
+[[Category: Bice, T W.]]
-[[Category: Narayana, S.V.]]
+[[Category: Narayana, S V.]]
 [[Category: Schneewind, O.]]
 [[Category: Ton-That, H.]]
@@ Line 22: / Line 22: @@
 [[Category: transpeptidase]]
-''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Sun Nov 25 01:32:30 2007''
+''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 15:09:12 2008''