Structural and functional analysis of Rv0554 from Mycobacterium tuberculosis: testing a putative role in menaquinone biosynthesis.
Mycobacterium tuberculosis, the cause of tuberculosis, is a devastating human pathogen against which new drugs are urgently needed. Enzymes from the biosynthetic pathway for menaquinone are considered to be valid drug targets. The protein encoded by the open reading frame Rv0554 has been expressed, purified and subjected to structural and functional analysis to test for a putative role in menaquinone biosynthesis. The crystal structure of Rv0554 has been solved and refined in two different space groups at 2.35 and 1.9 A resolution. The protein is dimeric, with an alpha/beta-hydrolase monomer fold. In each monomer, a large cavity adjacent to the catalytic triad is enclosed by a helical lid. Dimerization is mediated by the lid regions. Small-molecule additives used in crystallization bind in the active site, but no binding of ligands related to menaquinone biosynthesis could be detected and functional assays failed to support possible roles in menaquinone biosynthesis.
Johnston
Jodie M
JM
School of Biological Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand.
Jiang
Ming
M
Guo
Zhihong
Z
Baker
Edward N
EN
D018360:Crystallography, X-Ray; D008024:Ligands; D008958:Models, Molecular; D009169:Mycobacterium tuberculosis / Q000201:enzymology*; D009195:Peroxidase / Q000737:chemistry*; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D024482:Vitamin K 2 / Q000737:chemistry* / Q000378:metabolism
D008024:Ligands; D024482:Vitamin K 2; D009195:Peroxidase