Crystal and solution structures of an HslUV protease-chaperone complex.

M C Sousa; C B Trame; H Tsuruta; S M Wilbanks; V S Reddy; D B McKay

doi:10.1016/s0092-8674(00)00166-5

Home/Archive/PubMed

PubMed · 11106733

Crystal and solution structures of an HslUV protease-chaperone complex.

M C Sousa·C B Trame·H Tsuruta·S M Wilbanks·V S Reddy·D B McKay

View original source ↗Export metadata ↓

Abstract

HslUV is a "prokaryotic proteasome" composed of the HslV protease and the HslU ATPase, a chaperone of the Clp/Hsp100 family. The 3.4 A crystal structure of an HslUV complex is presented here. Two hexameric ATP binding rings of HslU bind intimately to opposite sides of the HslV protease; the HslU "intermediate domains" extend outward from the complex. The solution structure of HslUV, derived from small angle X-ray scattering data under conditions where the complex is assembled and active, agrees with this crystallographic structure. When the complex forms, the carboxy-terminal helices of HslU distend and bind between subunits of HslV, and the apical helices of HslV shift substantially, transmitting a conformational change to the active site region of the protease.

Explore related subjects

ATP-Dependent Proteases Adenosine Triphosphatases Bacterial Proteins Cloning, Molecular Crystallography, X-Ray Haemophilus influenzae Heat-Shock Proteins Hydrolysis Models, Molecular Molecular Chaperones Peptides Protein Structure, Quaternary Recombinant Proteins Scattering, Radiation Serine Endopeptidases Solutions Journal Article Research Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

M C Sousa, C B Trame, H Tsuruta, S M Wilbanks, V S Reddy, D B McKay. 2000-11-10. Crystal and solution structures of an HslUV protease-chaperone complex.. https://doi.org/10.1016/s0092-8674(00)00166-5

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2006

Variable and tissue-specific subunit composition of mitochondrial m-AAA protease complexes linked to hereditary spastic paraplegia.

The m-AAA protease, an ATP-dependent proteolytic complex in the mitochondrial inner membrane, controls protein quality and regulates ribosome assembly, thus exerting essential housekeeping functions within mitochondria. Mutations in the m-AAA protease subunit paraplegin cause axonal degeneration in hereditary spastic paraplegia (HSP), but the basis for the unexpected tissue specificity is not understood. Paraplegin assembles with homologous Afg3l2 subunits into hetero-oligomeric complexes which can substitute for yeast m-AAA proteases, demonstrating functional conservation. The function of a third paralogue, Afg3l1 expressed in mouse, is unknown. Here, we analyze the assembly of paraplegin into m-AAA complexes and monitor consequences of paraplegin deficiency in HSP fibroblasts and in a mouse model for HSP. Our findings reveal variability in the assembly of m-AAA proteases in mitochondria in different tissues. Homo-oligomeric Afg3l1 and Afg3l2 complexes and hetero-oligomeric assemblies of both proteins with paraplegin can be formed. Yeast complementation studies demonstrate the proteolytic activity of these assemblies. Paraplegin deficiency in HSP does not result in the loss of m-AAA protease activity in brain mitochondria. Rather, homo-oligomeric Afg3l2 complexes accumulate, and these complexes can substitute for housekeeping functions of paraplegin-containing m-AAA complexes. We therefore propose that the formation of m-AAA proteases with altered substrate specificities leads to axonal degeneration in HSP.

ATP-Dependent Proteases↗

PubMed2006

ATP-dependent proteases of bacteria: recognition logic and operating principles.

ATP-powered AAA+ proteases degrade specific proteins in intracellular environments occupied by thousands of different proteins. These proteases operate as powerful molecular machines that unfold stable native proteins before degradation. Understanding how these enzymes choose the "right" protein substrates at the "right" time is key to understanding their biological function. Recently, proteomic approaches have identified numerous substrates for some bacterial enzymes and the sequence motifs responsible for recognition. Advances have also been made in elucidating the mechanism and impact of adaptor proteins in regulating substrate choice. Finally, recent biochemical dissection of the ATPase cycle and its coupling to protein unfolding has revealed fundamental operating principles of this important, ubiquitous family of molecular machines.

ATP-Dependent Proteases↗

PubMed2006

Proteasome-related HslU and HslV genes typical of eubacteria are widespread in eukaryotes.

Many eubacteria contain an ATP-dependent protease complex, which is built by multiple copies of the HslV and HslU proteins and is therefore called HslVU. HslU proteins are AAA + ATPases, while HslV proteins are proteases that show highly significant similarity to beta subunits of proteasomes. Therefore, the HslVU complex has been envisaged as a precursor or ancestral type of proteasome. Here we show that species of most of the main eukaryotic lineages have HslU and HslV genes very similar to those found in proteobacteria. We have detected them in amoebozoa, plantae, chromoalveolata, rhizaria, and excavata species. Phylogenetic analyses suggest that these genes have been obtained by endosymbiosis from the proteobacterial ancestor that gave rise to eukaryotic mitochondria. The products encoded by these eukaryotic genes adopt, according to modeling based on the known crystal structures of prokaryotic HslU and HslV proteins, conformations that are compatible with their being fully active, suggesting that functional HslVU complexes may be present in many eukaryotic species.

ATP-Dependent Proteases↗