1a2n: Difference between revisions

From Proteopedia
Jump to navigation Jump to search
No edit summary
No edit summary
Line 1: Line 1:
[[Image:1a2n.jpg|left|200px]]
{{Seed}}
[[Image:1a2n.png|left|200px]]


<!--
<!--
Line 9: Line 10:
{{STRUCTURE_1a2n|  PDB=1a2n  |  SCENE=  }}  
{{STRUCTURE_1a2n|  PDB=1a2n  |  SCENE=  }}  


'''STRUCTURE OF THE C115A MUTANT OF MURA COMPLEXED WITH THE FLUORINATED ANALOG OF THE REACTION TETRAHEDRAL INTERMEDIATE'''
===STRUCTURE OF THE C115A MUTANT OF MURA COMPLEXED WITH THE FLUORINATED ANALOG OF THE REACTION TETRAHEDRAL INTERMEDIATE===




==Overview==
<!--
MurA (UDP-GlcNAc enolpyruvyl transferase), the first enzyme in bacterial peptidoglycan biosynthesis, catalyzes the enolpyruvyl transfer from phosphoenolpyruvate (PEP) to the 3'-OH of UDP-GlcNAc by an addition-elimination mechanism that proceeds through a tetrahedral ketal intermediate. The crystal structure of the Cys115-to-Ala (C115A) mutant of Escherichia coli MurA complexed with a fluoro analogue of the tetrahedral intermediate revealed the absolute configuration of the adduct and the stereochemical course of the reaction. The fluorinated adduct was generated in a preincubation of wild-type MurA with (Z)-3-fluorophosphoenolpyruvate (FPEP) and UDP-GlcNAc and purified after enzyme denaturation. The fluorine substituent stabilizes the tetrahedral intermediate toward decomposition by a factor of 10(4)-10(6), facilitating manipulation of the adduct. The C115A mutant of MurA was utilized to avoid the microheterogeneity that arises in the wild-type MurA from the attack of Cys115 on C-2 of FPEP in competition with the formation of the fluorinated adduct. The crystal structure of the complex was determined to 2.8 A resolution, and the absolute configuration at C-2 of the adduct was found to be 2R. Thus, addition of the 3'-OH of UDP-GlcNAc is to the 2-si face of FPEP, corresponding to the 2-re face of PEP. Given the previous observation that, in D2O, the addition of D+ to C-3 of PEP proceeds from the 2-si face [Kim, D. H., Lees, W. J., and Walsh, C. T. (1995) J. Am. Chem. Soc. 117, 6380-6381], the addition across the double bond of PEP is anti. Also, because the overall stereochemical course has been shown to be either anti/syn or syn/anti [Lees, W. J., and Walsh, C. T. (1995) J. Am. Chem. Soc. 117, 7329-7337], it now follows that the stereochemistry of elimination of H+ from C-3 and Pi from C-2 of the tetrahedral intermediate of the reaction is syn.
The line below this paragraph, {{ABSTRACT_PUBMED_9485407}}, adds the Publication Abstract to the page
(as it appears on PubMed at http://www.pubmed.gov), where 9485407 is the PubMed ID number.
-->
{{ABSTRACT_PUBMED_9485407}}


==About this Structure==
==About this Structure==
Line 28: Line 32:
[[Category: Transferase]]
[[Category: Transferase]]
[[Category: Udp-n-acetylglucosamine]]
[[Category: Udp-n-acetylglucosamine]]
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Fri May  2 09:43:02 2008''
 
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Mon Jun 30 15:52:03 2008''

Revision as of 15:52, 30 June 2008

File:1a2n.png

Template:STRUCTURE 1a2n

STRUCTURE OF THE C115A MUTANT OF MURA COMPLEXED WITH THE FLUORINATED ANALOG OF THE REACTION TETRAHEDRAL INTERMEDIATESTRUCTURE OF THE C115A MUTANT OF MURA COMPLEXED WITH THE FLUORINATED ANALOG OF THE REACTION TETRAHEDRAL INTERMEDIATE

Template:ABSTRACT PUBMED 9485407

About this StructureAbout this Structure

1A2N is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.

ReferenceReference

Stereochemical course of enzymatic enolpyruvyl transfer and catalytic conformation of the active site revealed by the crystal structure of the fluorinated analogue of the reaction tetrahedral intermediate bound to the active site of the C115A mutant of MurA., Skarzynski T, Kim DH, Lees WJ, Walsh CT, Duncan K, Biochemistry. 1998 Feb 24;37(8):2572-7. PMID:9485407

Page seeded by OCA on Mon Jun 30 15:52:03 2008

Proteopedia Page Contributors and Editors (what is this?)Proteopedia Page Contributors and Editors (what is this?)

OCA