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2g0f
From Proteopedia
(New page: 200px<br /><applet load="2g0f" size="450" color="white" frame="true" align="right" spinBox="true" caption="2g0f, resolution 2.20Å" /> '''Crystal Structure of...) |
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| - | [[Image:2g0f.gif|left|200px]]<br /><applet load="2g0f" size=" | + | [[Image:2g0f.gif|left|200px]]<br /><applet load="2g0f" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="2g0f, resolution 2.20Å" /> | caption="2g0f, resolution 2.20Å" /> | ||
'''Crystal Structure of P144A mutant of E.coli CcmG protein'''<br /> | '''Crystal Structure of P144A mutant of E.coli CcmG protein'''<br /> | ||
==Overview== | ==Overview== | ||
| - | CcmG, also designated DsbE, functions as a periplasmic protein | + | CcmG, also designated DsbE, functions as a periplasmic protein thiol:disulfide oxidoreductase and is required for cytochrome c maturation. Here we report the crystal structures of Escherichia coli CcmG and its two mutants, P144A and the N-terminal fifty seven-residue deletion mutant, and two additional deletion mutants were studied by circular dichroism. Structural comparison of E. coli CcmG with its deletion mutants reveals that the N-terminal beta-sheet is essential for maintaining the folding topology and consequently maintaining the active-site structure of CcmG. Pro144 and Glu145 are key residues of the fingerprint region of CcmG. Pro144 is in cis-configuration, and it makes van der Waals interactions with the active-site disulfide Cys80-Cys83 and forms a C--H...O hydrogen bond with Thr82, helping stabilize the active-site structure. Glu145 forms a salt-bridge and hydrogen-bond network with other residues of the fingerprint region and with Arg158, further stabilizing the active-site structure. The cis-configuration of Pro144 makes the backbone nitrogen and oxygen of Ala143 exposed to solvent, favorable for interacting with binding partners. The key role of cis-Pro144 is verified by the P144A mutant, which contains trans-Ala144 and displays redox property changes. Structural comparison of E. coli CcmG with the recently reported structure of CcmG in complex with the N-terminal domain of DsbD reveals that Tyr141 undergoes conformational changes upon binding DsbD. A cis-proline located at the N-terminus of the first beta-strand of the betabetaalpha motif of the thioredoxin-like domain is a conserved structural feature of the thioredoxin superfamily. |
==About this Structure== | ==About this Structure== | ||
| - | 2G0F is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http:// | + | 2G0F is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2G0F OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Escherichia coli]] | [[Category: Escherichia coli]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Gao, Y | + | [[Category: Gao, Y G.]] |
| - | [[Category: Hu, H | + | [[Category: Hu, H Y.]] |
[[Category: Ouyang, N.]] | [[Category: Ouyang, N.]] | ||
| - | [[Category: Xia, Z | + | [[Category: Xia, Z X.]] |
[[Category: cis-to-trans configuration change]] | [[Category: cis-to-trans configuration change]] | ||
| - | [[Category: e | + | [[Category: e coli ccmg]] |
[[Category: p144a mutant]] | [[Category: p144a mutant]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 17:27:02 2008'' |
Revision as of 15:27, 21 February 2008
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Crystal Structure of P144A mutant of E.coli CcmG protein
Overview
CcmG, also designated DsbE, functions as a periplasmic protein thiol:disulfide oxidoreductase and is required for cytochrome c maturation. Here we report the crystal structures of Escherichia coli CcmG and its two mutants, P144A and the N-terminal fifty seven-residue deletion mutant, and two additional deletion mutants were studied by circular dichroism. Structural comparison of E. coli CcmG with its deletion mutants reveals that the N-terminal beta-sheet is essential for maintaining the folding topology and consequently maintaining the active-site structure of CcmG. Pro144 and Glu145 are key residues of the fingerprint region of CcmG. Pro144 is in cis-configuration, and it makes van der Waals interactions with the active-site disulfide Cys80-Cys83 and forms a C--H...O hydrogen bond with Thr82, helping stabilize the active-site structure. Glu145 forms a salt-bridge and hydrogen-bond network with other residues of the fingerprint region and with Arg158, further stabilizing the active-site structure. The cis-configuration of Pro144 makes the backbone nitrogen and oxygen of Ala143 exposed to solvent, favorable for interacting with binding partners. The key role of cis-Pro144 is verified by the P144A mutant, which contains trans-Ala144 and displays redox property changes. Structural comparison of E. coli CcmG with the recently reported structure of CcmG in complex with the N-terminal domain of DsbD reveals that Tyr141 undergoes conformational changes upon binding DsbD. A cis-proline located at the N-terminus of the first beta-strand of the betabetaalpha motif of the thioredoxin-like domain is a conserved structural feature of the thioredoxin superfamily.
About this Structure
2G0F is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.
Reference
Crystal structures of E. coli CcmG and its mutants reveal key roles of the N-terminal beta-sheet and the fingerprint region., Ouyang N, Gao YG, Hu HY, Xia ZX, Proteins. 2006 Dec 1;65(4):1021-31. PMID:17019698
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