Journal
BIOCHEMISTRY
Volume 47, Issue 39, Pages 10354-10364Publisher
AMER CHEMICAL SOC
DOI: 10.1021/bi800915j
Keywords
-
Categories
Funding
- National Institutes of Health [DK44083, DK67081, RR15301]
Ask authors/readers for more resources
The structure of the protein complex CysM-CysO from a new cysteine biosynthetic pathway found in the H37Rv strain of Mycobacterium tuberculosis has been determined at 1.53 angstrom resolution. CysM (Rv 1336) is a PLP-containing beta-replacement enzyme and CysO (Rv 1335) is a sulfur carrier protein with a ubiquitin-like fold. CysM catalyzes the replacement of the acetyl group of O-acetylserine by CysO thiocarboxylate to generate a protein-bound cysteine that is released in a subsequent proteolysis reaction. The protein complex in the crystal structure is asymmetric with one CysO protomer binding to one end of a CysM dimer. Additionally, the structures of CysM and CysO were determined individually at 2.8 and 2.7 angstrom resolution, respectively. Sequence alignments with homologues and structural comparisons with CysK, a cysteine synthase that does not utilize a sulfur carrier protein, revealed high conservation of active site residues; however, residues in CysM responsible for CysO binding are not conserved. Comparison of the CysM-CysO binding interface with other sulfur carrier protein complexes revealed a similarity in secondary structural elements that contribute to complex formation in the ThiF-ThiS and MoeB-MoaD systems, despite major differences in overall folds. Comparison of CysM with and without bound CysO revealed conformational changes associated with CysO binding.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available