1NFQ

Rv2002 gene product from Mycobacterium tuberculosis

Summary for 1NFQ

• Entry DOI: 10.2210/pdb1nfq/pdb
• Related: 1NFF 1NFR
• Descriptor: Putative oxidoreductase Rv2002, 1,4-DIHYDRONICOTINAMIDE ADENINE DINUCLEOTIDE, Androsterone, ... (4 entities in total)
• Functional Keywords: directed evolution, sdr, gfp, hydroxysteroid dehydrogenase, structural genomics, psi, protein structure initiative, tb structural genomics consortium, tbsgc, oxidoreductase
• Biological source: Mycobacterium tuberculosis
• Total number of polymer chains: 4
• Total formula weight: 112230.44

Authors

Yang, J.K.,Park, M.S.,Waldo, G.S.,Suh, S.W.,TB Structural Genomics Consortium (TBSGC) (deposition date: 2002-12-15, release date: 2002-12-30, Last modification date: 2024-05-29)

Primary citation

Yang, J.K.,Park, M.S.,Waldo, G.S.,Suh, S.W.
Directed evolution approach to a structural genomics project: Rv2002 from Mycobacterium tuberculosis
Proc.Natl.Acad.Sci.USA, 100:455-460, 2003

PubMed Abstract: One of the serious bottlenecks in structural genomics projects is overexpression of the target proteins in soluble form. We have applied the directed evolution technique and prepared soluble mutants of the Mycobacterium tuberculosis Rv2002 gene product, the wild type of which had been expressed as inclusion bodies in Escherichia coli. A triple mutant I6TV47MT69K (Rv2002-M3) was chosen for structural and functional characterizations. Enzymatic assays indicate that the Rv2002-M3 protein has a high catalytic activity as a NADH-dependent 3alpha, 20beta-hydroxysteroid dehydrogenase. We have determined the crystal structures of a binary complex with NAD(+) and a ternary complex with androsterone and NADH. The structure reveals that Asp-38 determines the cofactor specificity. The catalytic site includes the triad Ser-140Tyr-153Lys-157. Additionally, it has an unusual feature, Glu-142. Enzymatic assays of the E142A mutant of Rv2002-M3 indicate that Glu-142 reverses the effect of Lys-157 in influencing the pKa of Tyr-153. This study suggests that the Rv2002 gene product is a unique member of the SDR family and is likely to be involved in steroid metabolism in M. tuberculosis. Our work demonstrates the power of the directed evolution technique as a general way of overcoming the difficulties in overexpressing the target proteins in soluble form.

PubMed: 12524453
DOI: 10.1073/pnas.0137017100

Experimental method

X-RAY DIFFRACTION (2.4 Å)