3p32

Publication Abstract from PubMed

The methylmalonyl Co-A mutase-associated GTPase MeaB from Methylobacterium extorquens is involved in glyoxylate regulation and required for growth. In humans, mutations in the homolog methylmalonic aciduria associated protein (MMAA) cause methylmalonic aciduria, which is often fatal. The central role of MeaB from bacteria to humans suggests that MeaB is also important in other, pathogenic bacteria such as Mycobacterium tuberculosis. However, the identity of the mycobacterial MeaB homolog is presently unclear. Here, we identify the M. tuberculosis protein Rv1496 and its homologs in M. smegmatis and M. thermoresistibile as MeaB. The crystal structures of all three homologs are highly similar to MeaB and MMAA structures and reveal a characteristic three-domain homodimer with GDP bound in the G domain active site. A structure of Rv1496 obtained from a crystal grown in the presence of GTP exhibited electron density for GDP, suggesting GTPase activity. These structures identify the mycobacterial MeaB and provide a structural framework for therapeutic targeting of M. tuberculosis MeaB.

Crystal structures of Mycobacterial MeaB and MMAA-like GTPases.,Edwards TE, Baugh L, Bullen J, Baydo RO, Witte P, Thompkins K, Phan IQ, Abendroth J, Clifton MC, Sankaran B, Van Voorhis WC, Myler PJ, Staker BL, Grundner C, Lorimer DD J Struct Funct Genomics. 2015 Jun;16(2):91-9. doi: 10.1007/s10969-015-9197-2., Epub 2015 Apr 2. PMID:25832174^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.