Homotypic dimerization of a maltose kinase for molecular scaffolding.

ABSTRACT: Mycobacterium tuberculosis (Mtb) uses maltose-1-phosphate to synthesize α-glucans that make up the major component of its outer capsular layer. Maltose kinase (MaK) catalyzes phosphorylation of maltose. The molecular basis for this phosphorylation is currently not understood. Here, we describe the first crystal structure of MtbMaK refined to 2.4 Å resolution. The bi-modular architecture of MtbMaK reveals a remarkably unique N-lobe. An extended sheet protrudes into ligand binding pocket of an adjacent monomer and contributes residues critical for kinase activity. Structure of the complex of MtbMaK bound with maltose reveals that maltose binds in a shallow cavity of the C-lobe. Structural constraints permit phosphorylation of α-maltose only. Surprisingly, instead of a Gly-rich loop, MtbMaK e

SUBMITTER: Li J 

PROVIDER: S-EPMC4171701 | biostudies-literature | 2014 Sep

REPOSITORIES: biostudies-literature