1L1J

Crystal structure of the protease domain of an ATP-independent heat shock protease HtrA

Summary for 1L1J

• Entry DOI: 10.2210/pdb1l1j/pdb
• Descriptor: heat shock protease HtrA (2 entities in total)
• Functional Keywords: hydrolase, serine proteinase
• Biological source: Thermotoga maritima
• Total number of polymer chains: 2
• Total formula weight: 51862.91

Authors

Kim, D.Y.,Kim, D.R.,Ha, S.C.,Lokanath, N.K.,Hwang, H.Y.,Kim, K.K. (deposition date: 2002-02-18, release date: 2003-04-01, Last modification date: 2024-03-13)

Primary citation

Kim, D.Y.,Kim, D.R.,Ha, S.C.,Lokanath, N.K.,Lee, C.J.,Hwang, H.Y.,Kim, K.K.
Crystal Structure of the Protease Domain of a Heat-shock Protein HtrA from Thermotoga maritima
J.BIOL.CHEM., 278:6543-6551, 2003

PubMed Abstract: HtrA (high temperature requirement A), a periplasmic heat-shock protein, functions as a molecular chaperone at low temperatures, and its proteolytic activity is turned on at elevated temperatures. To investigate the mechanism of functional switch to protease, we determined the crystal structure of the NH(2)-terminal protease domain (PD) of HtrA from Thermotoga maritima, which was shown to retain both proteolytic and chaperone-like activities. Three subunits of HtrA PD compose a trimer, and multimerization architecture is similar to that found in the crystal structures of intact HtrA hexamer from Escherichia coli and human HtrA2 trimer. HtrA PD shares the same fold with chymotrypsin-like serine proteases, but it contains an additional lid that blocks access the of substrates to the active site. A corresponding lid found in E. coli HtrA is a long loop that also blocks the active site of another subunit. These results suggest that the activation of the proteolytic function of HtrA at elevated temperatures might occur by a conformational change, which includes the opening of the helical lid to expose the active site and subsequent rearrangement of a catalytic triad and an oxyanion hole.

PubMed: 12458220
DOI: 10.1074/jbc.M208148200

Experimental method

X-RAY DIFFRACTION (2.8 Å)