4jn6

Crystal Structure of the Aldolase-Dehydrogenase Complex from Mycobacterium tuberculosis HRv37Crystal Structure of the Aldolase-Dehydrogenase Complex from Mycobacterium tuberculosis HRv37

Structural highlights 4jn6 is a 4 chain structure with sequence from Mycobacterium tuberculosis. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.93Å Ligands: , , Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function HOA_MYCTU Catalyzes the retro-aldol cleavage of 4-hydroxy-2-oxopentanoate to pyruvate and acetaldehyde. Is involved in the meta-cleavage pathway for the degradation of aromatic compounds (By similarity). Publication Abstract from PubMed HsaF and HsaG are an aldolase and dehydrogenase from the cholesterol degradation pathway of M. tuberculosis. HsaF could be heterologously expressed and purified as a soluble dimer, but the enzyme was inactive in the absence of HsaG. HsaF catalyzes the aldol cleavage of 4-hydroxy-2-oxoacids to produce pyruvate and an aldehyde. The enzyme requires divalent metals for activity, with a preference for Mn2+. The Km values for 4-hydroxy-2-oxoacids were about 20-fold lower than observed for the aldolase homologue, BphI from the polychlorinated biphenyl degradation pathway. Acetaldehyde and propionaldehyde were channeled directly to the dehydrogenase, HsaG, without export to the bulk solvent where they were transformed to acyl-CoA in an NAD+ and coenzyme A dependent reaction. HsaG is able to utilize aldehydes up to five carbons in length as substrates, with similar catalytic efficiencies. The HsaF-HsaG complex was crystallized and its structure determined to a resolution of 1.93 A. Substitution of Serine 41 in HsaG with isoleucine or aspartate resulted in about 35-fold increase in Km for CoA but only 4-fold increase in Km dephospho-CoA, suggesting that this residue interacts with the 3'-ribose phosphate of CoA. A second protein annotated as a 4-hydroxy-2-oxopentanoic acid aldolase in Mycobacterium tuberculosis (MhpE, Rv3469c) was expressed and purified, but was found to lack aldolase activity. Instead this enzyme was found to possess oxaloacetate decarboxylase activity, consistent with the conservation (with the 4-hydroxy-2-oxoacid aldolases) of residues involved in pyruvate enolate stabilization. Characterization of an aldolase-dehydrogenase complex from the cholesterol degradation pathway of Mycobacterium tuberculosis.,Carere J, McKenna SE, Kimber MS, Seah SY Biochemistry. 2013 Apr 24. PMID:23614353 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Aldolase 3D structures

spinqualitylabelsall models 4jn6, resolution 1.93Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image