Structure of isocitrate lyase, a persistence factor of Mycobacterium tuberculosis.
Isocitrate lyase (ICL) plays a pivotal role in the persistence of Mycobacterium tuberculosis in mice by sustaining intracellular infection in inflammatory macrophages. The enzyme allows net carbon gain by diverting acetyl-CoA from beta-oxidation of fatty acids into the glyoxylate shunt pathway. Given its potential as a drug target against persistent infections, we solved its structure without ligand and in complex with two inhibitors. Covalent modification of an active site residue, Cys 191, by the inhibitor 3-bromopyruvate traps the enzyme in a catalytic conformation with the active site completely inaccessible to solvent. The structure of a C191S mutant of the enzyme with the inhibitor 3-nitropropionate provides further insight into the reaction mechanism.
Department of Biochemistry and Biophysics, Texas A&M University, College Station, Texas 77843-2128, USA.
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V
Sharma
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Sharma
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Hoener zu Bentrup
J D
JD
McKinney
D G
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Russell
W R
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Jacobs
J C
JC
Sacchettini
D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D001665:Binding Sites; D002384:Catalysis / Q000187:drug effects; D018360:Crystallography, X-Ray; D003545:Cysteine / Q000235:genetics / Q000378:metabolism; D006038:Glyoxylates / Q000737:chemistry / Q000378:metabolism; D007522:Isocitrate Lyase / Q000037:antagonists & inhibitors / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008024:Ligands; D051379:Mice; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D009169:Mycobacterium tuberculosis / Q000201:enzymology* / Q000472:pathogenicity*; D009574:Nitro Compounds; D011422:Propionates / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D011485:Protein Binding; D017433:Protein Structure, Secondary / Q000187:drug effects; D017434:Protein Structure, Tertiary / Q000187:drug effects; D011773:Pyruvates / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D012997:Solvents
D006038:Glyoxylates; D008024:Ligands; D009574:Nitro Compounds; D011422:Propionates; D011773:Pyruvates; D012997:Solvents; C017092:bromopyruvate; D007522:Isocitrate Lyase; C031150:glyoxylic acid; D003545:Cysteine; C015392:3-nitropropionic acid