Tracing an allosteric pathway regulating the activity of the HslV protease.

ABSTRACT: The HslU-HslV complex functions as a bacterial proteasome, degrading substrate polypeptides to preserve cellular homeostasis. Here, we use methyl-Transverse Relaxation-Optimized Spectroscopy (TROSY) and highly deuterated, methyl-protonated samples to study the 230 kDa dodecameric HslV protease component that is structurally homologous to the stacked pair of β7-rings of the proteasome. Chemical shift assignments for over 95% of the methyl groups are reported. From the pH dependence of methyl chemical shifts, a pKa of 7.7 is measured for the amine group of the catalytic residue T1, confirming that it can act as a proton acceptor during the initial step in substrate proteolysis. Analyses involving a series of single site mutants in HslV, localized to HslU binding sites or regions undergoing s

SUBMITTER: Shi L 

PROVIDER: S-EPMC3926032 | biostudies-literature | 2014 Feb

REPOSITORIES: biostudies-literature