1.55 Å resolution X-ray crystal structure of Rv3902c fromMycobacterium tuberculosis

Abstract

The crystallographic structure of the Mycobacterium tuberculosis (TB) protein Rv3902c (176 residues; molecular mass of 19.8 kDa) was determined at 1.55 Å resolution. The function of Rv3902c is unknown, although several TB genes involved in bacterial pathogenesis are expressed from the operon containing the Rv3902c gene. The unique structural fold of Rv3902c contains two domains, each consisting of antiparallel -sheets and -helices, creating a hand-like binding motif with a small binding pocket in the palm. Structural homology searches reveal that Rv3902c has an overall structure similar to that of the Salmonella virulence-factor chaperone InvB, with an r.m.s.d. for main-chain atoms of 2.3 Å along an aligned domain.

The tuberculosis necrotizing toxin kills macrophages by hydrolyzing NAD

“…3c , 4a ) that penetrate deeply inside the TNT core and make extensive electrostatic contacts. Although the structure of IFT in complex with TNT superimposes well to the structure of free IFT 26 (rmsd ~0.52 Å), the side chain conformations in the TNT-interaction loops (N36, K37, E40, and D58, R59, M60, S61) projecting inside the TNT crevice are different ( Fig. 3c ).…”