5TXV

HslU P21 cell with 4 hexamers

Summary for 5TXV

• Entry DOI: 10.2210/pdb5txv/pdb
• Descriptor: ATP-dependent protease ATPase subunit HslU, ADENOSINE-5'-DIPHOSPHATE (2 entities in total)
• Functional Keywords: aaa+ atpase, hydrolase
• Biological source: Escherichia coli (strain K12)
• Total number of polymer chains: 24
• Total formula weight: 1198937.02

Authors

Grant, R.A.,Chen, J.,Glynn, S.E.,Sauer, R.T. (deposition date: 2016-11-17, release date: 2017-03-01, Last modification date: 2023-10-04)

Primary citation

Baytshtok, V.,Chen, J.,Glynn, S.E.,Nager, A.R.,Grant, R.A.,Baker, T.A.,Sauer, R.T.
Covalently linked HslU hexamers support a probabilistic mechanism that links ATP hydrolysis to protein unfolding and translocation.
J. Biol. Chem., 292:5695-5704, 2017

PubMed Abstract: The HslUV proteolytic machine consists of HslV, a double-ring self-compartmentalized peptidase, and one or two AAA+ HslU ring hexamers that hydrolyze ATP to power the unfolding of protein substrates and their translocation into the proteolytic chamber of HslV. Here, we use genetic tethering and disulfide bonding strategies to construct HslU pseudohexamers containing mixtures of ATPase active and inactive subunits at defined positions in the hexameric ring. Genetic tethering impairs HslV binding and degradation, even for pseudohexamers with six active subunits, but disulfide-linked pseudohexamers do not have these defects, indicating that the peptide tether interferes with HslV interactions. Importantly, pseudohexamers containing different patterns of hydrolytically active and inactive subunits retain the ability to unfold protein substrates and/or collaborate with HslV in their degradation, supporting a model in which ATP hydrolysis and linked mechanical function in the HslU ring operate by a probabilistic mechanism.

PubMed: 28223361
DOI: 10.1074/jbc.M116.768978

Experimental method

X-RAY DIFFRACTION (7.086 Å)