2ns6 | pdb_00002ns6
Crystal Structure of the Minimal Relaxase Domain of MobA from Plasmid R1162
|
Overview
The plasmid R1162 encodes proteins that enable its conjugative, mobilization between bacterial cells. It can transfer between many, different species and is one of the most promiscuous of the mobilizable, plasmids. The plasmid-encoded protein MobA, which has both nicking and, priming activities on single-stranded DNA, is essential for mobilization., The nicking, or relaxase, activity has been localized to the 186 residue, N-terminal domain, called minMobA. We present here the 2.1 A X-ray, structure of minMobA. The fold is similar to that seen for two other, relaxases, TraI and TrwC. The similarity in fold, and action, suggests, these enzymes are evolutionary homologs, despite the lack of any, significant amino acid similarity. MinMobA has a well- defined target DNA, called oriT. The active site metal is observed near Tyr25, which is known, to form a phosphotyrosine adduct with the substrate. A model of the oriT, substrate complexed with minMobA has been made, based on observed, substrate binding to TrwC and TraI. The model is consistent with, observations of substrate base specificity, and provides a rationalization, for elements of the likely enzyme mechanism.
About this Structure
2NS6 is a Protein complex structure of sequences from Pseudomonas aeruginosa with MN as ligand. Full crystallographic information is available from OCA.
Reference
The structure of the minimal relaxase domain of MobA at 2.1 A resolution., Monzingo AF, Ozburn A, Xia S, Meyer RJ, Robertus JD, J Mol Biol. 2007 Feb 9;366(1):165-78. Epub 2006 Nov 11. PMID:17157875
Page seeded by OCA on Tue Jan 29 20:58:54 2008
