1x9z

From Proteopedia

Revision as of 13:07, 20 March 2008

Crystal structure of the MutL C-terminal domain

Overview

MutL assists the mismatch recognition protein MutS to initiate and coordinate mismatch repair in species ranging from bacteria to humans. The MutL N-terminal ATPase domain is highly conserved, but the C-terminal region shares little sequence similarity among MutL homologs. We report here the crystal structure of the Escherichia coli MutL C-terminal dimerization domain and the likelihood of its conservation among MutL homologs. A 100-residue proline-rich linker between the ATPase and dimerization domains, which generates a large central cavity in MutL dimers, tolerates sequence substitutions and deletions of one-third of its length with no functional consequences in vivo or in vitro. Along the surface of the central cavity, residues essential for DNA binding are located in both the N- and C-terminal domains. Each domain of MutL interacts with UvrD helicase and is required for activating the helicase activity. The DNA-binding capacity of MutL is correlated with the level of UvrD activation. A model of how MutL utilizes its ATPase and DNA-binding activities to mediate mismatch-dependent activation of MutH endonuclease and UvrD helicase is proposed.

About this Structure

1X9Z is a Single protein structure of sequence from Escherichia coli. Full crystallographic information is available from OCA.

Reference

Structure of the MutL C-terminal domain: a model of intact MutL and its roles in mismatch repair., Guarne A, Ramon-Maiques S, Wolff EM, Ghirlando R, Hu X, Miller JH, Yang W, EMBO J. 2004 Oct 27;23(21):4134-45. Epub 2004 Oct 7. PMID:15470502

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