3DWI

Crystal structure of Mycobacterium tuberculosis CysM, the cysteine synthase B

Summary for 3DWI

• Entry DOI: 10.2210/pdb3dwi/pdb
• Related: 3DWG 3DWM
• Descriptor: Cysteine synthase B, SULFATE ION, PYRIDOXAL-5'-PHOSPHATE, ... (4 entities in total)
• Functional Keywords: cysteine synthase, amino-acid biosynthesis, cysteine biosynthesis, pyridoxal phosphate, transferase
• Biological source: Mycobacterium tuberculosis
• Total number of polymer chains: 2
• Total formula weight: 69610.01

Authors

Jurgenson, C.T.,Burns, K.E.,Begley, T.P.,Ealick, S.E. (deposition date: 2008-07-22, release date: 2008-09-23, Last modification date: 2023-08-30)

Primary citation

Jurgenson, C.T.,Burns, K.E.,Begley, T.P.,Ealick, S.E.
Crystal structure of a sulfur carrier protein complex found in the cysteine biosynthetic pathway of Mycobacterium tuberculosis.
Biochemistry, 47:10354-10364, 2008

PubMed Abstract: 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 A resolution. CysM (Rv1336) is a PLP-containing beta-replacement enzyme and CysO (Rv1335) 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 A 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.

PubMed: 18771296
DOI: 10.1021/bi800915j

Experimental method

X-RAY DIFFRACTION (2.81 Å)