2avw
From Proteopedia
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Crystal structure of monoclinic form of streptococcus Mac-1
Overview
Group A Streptococcus secretes cysteine proteases named Mac-1 and Mac-2 that mediate host immune evasion by targeting both IgG and Fc receptors. Here, we report the crystal structures of Mac-1 and its catalytically inactive C94A mutant in two different crystal forms. Despite the lack of sequence homology, Mac-1 adopts the canonical papain fold. Alanine mutations at the active site confirmed the critical residues involved in a papain-like catalytic mechanism. Mac-1 forms a symmetric dimer in both crystal forms and displays the unique dimer interface among papain superfamily members. Mutations at the dimer interface resulted in a significant reduction in IgG binding and catalysis, suggesting that the dimer contributes to both IgG specificity and enzyme cooperativity. A tunnel observed at the dimer interface constitutes a target for designing potential Mac-1-specific antimicrobial agents. The structures also offer insight into the functional difference between Mac-1 and Mac-2.
About this Structure
2AVW is a Single protein structure of sequence from Streptococcus pyogenes mgas315 with and as ligands. Full crystallographic information is available from OCA.
Reference
Crystal structure of group A streptococcus Mac-1: insight into dimer-mediated specificity for recognition of human IgG., Agniswamy J, Nagiec MJ, Liu M, Schuck P, Musser JM, Sun PD, Structure. 2006 Feb;14(2):225-35. PMID:16472742
Page seeded by OCA on Thu Feb 21 16:31:38 2008
Categories: Single protein | Streptococcus pyogenes mgas315 | Agniswamy, J. | Liu, M. | Musser, J M. | Nagiec, M J. | Schuck, P. | Sun, P D. | GOL | SO4 | Mac-1
