title: Crystal structure of a sulfur carrier protein complex found in the cysteine biosynthetic pathway of Mycobacterium tuberculosis.
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.
authors.affiliation: Department of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853-1301, USA.
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Jurgenson
authors.forename: Kristin E
authors.initials: KE
authors.lastname: Burns
authors.forename: Tadhg P
authors.initials: TP
authors.lastname: Begley
authors.forename: Steven E
authors.initials: SE
authors.lastname: Ealick
mesh_terms: D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D003545:Cysteine / Q000096:biosynthesis*; D003547:Cysteine Synthase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D017931:DNA Primers; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D008715:Methionine / Q000378:metabolism; D008958:Models, Molecular; D009169:Mycobacterium tuberculosis / Q000378:metabolism*; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D013455:Sulfur / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D017931:DNA Primers; D029968:Escherichia coli Proteins; D011994:Recombinant Proteins; D013455:Sulfur; D008715:Methionine; D003547:Cysteine Synthase; C513541:cysM protein, E coli; D003545:Cysteine
references.citation: Acta Crystallogr D Biol Crystallogr. 1994 Sep 1;50(Pt 5):760-3
references.pmid: 15299374
references.citation: Annu Rev Cell Dev Biol. 2004;20:367-94
references.pmid: 15473845
references.citation: Biochemistry. 2004 Sep 21;43(37):11647-57
references.pmid: 15362849
references.citation: J Biomol NMR. 2006 Feb;34(2):89-100
references.pmid: 16518696
references.citation: Protein Sci. 1995 May;4(5):849-54
references.pmid: 7663340
references.citation: Arch Microbiol. 1999 Apr;171(5):293-300
references.pmid: 10382260
references.citation: Anal Biochem. 1976 May 7;72:248-54
references.pmid: 942051
references.citation: Nature. 2001 Nov 15;414(6861):325-9
references.pmid: 11713534
references.citation: Acc Chem Res. 2001 Jan;34(1):49-59
references.pmid: 11170356
references.citation: Acta Crystallogr D Biol Crystallogr. 1998 Sep 1;54(Pt 5):905-21
references.pmid: 9757107
references.citation: Mol Microbiol. 2002 Jul;45(2):365-74
references.pmid: 12123450
references.citation: Prog Biophys Mol Biol. 1995;63(1):31-65
references.pmid: 7746868
references.citation: Biochemistry. 2006 Jan 10;45(1):11-9
references.pmid: 16388576
references.citation: Nat Struct Biol. 2001 Jan;8(1):42-6
references.pmid: 11135669
references.citation: J Biol Chem. 2001 Sep 14;276(37):34695-701
references.pmid: 11463785
references.citation: J Bacteriol. 2007 Apr;189(7):2941-4
references.pmid: 17209031
references.citation: Methods Enzymol. 1997;276:307-26
references.pmid: 27754618
references.citation: J Biol Chem. 1998 Jun 26;273(26):16555-60
references.pmid: 9632726
references.citation: Acta Crystallogr D Biol Crystallogr. 2000 Aug;56(Pt 8):965-72
references.pmid: 10944333
references.citation: Proc Natl Acad Sci U S A. 1985 Jun;82(11):3582-5
references.pmid: 2987935
references.citation: Acta Crystallogr A. 1991 Mar 1;47 ( Pt 2):110-9
references.pmid: 2025413
references.citation: Clin Immunol. 2005 Mar;114(3):239-47
references.pmid: 15721834
references.citation: J Infect Dis. 1998 Apr;177(4):1030-5
references.pmid: 9534978
references.citation: J Comput Chem. 1986 Apr;7(2):230-252
references.pmid: 29160584
references.citation: J Am Chem Soc. 2005 Aug 24;127(33):11602-3
references.pmid: 16104727
references.citation: Acta Crystallogr D Biol Crystallogr. 2004 Dec;60(Pt 12 Pt 1):2126-32
references.pmid: 15572765
references.citation: Acta Crystallogr D Biol Crystallogr. 2003 Jan;59(Pt 1):38-44
references.pmid: 12499537
references.citation: J Mol Biol. 1998;283(1):121-33
references.pmid: 9761678
references.citation: Nat Cell Biol. 2003 Sep;5(9):776-8
references.pmid: 12951608
references.citation: Proc Natl Acad Sci U S A. 2001 Jul 17;98(15):8513-8
references.pmid: 11438688
references.citation: Acta Crystallogr D Biol Crystallogr. 1999 Apr;55(Pt 4):849-61
references.pmid: 10089316
references.citation: J Mol Biol. 1999 Aug 27;291(4):941-53
references.pmid: 10452898
references.citation: Structure. 2004 Apr;12(4):529-35
references.pmid: 15062076
references.citation: J Immunol. 1989 Mar 1;142(5):1696-701
references.pmid: 2537362