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1atr

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THREONINE 204 OF THE CHAPERONE PROTEIN HSC70 INFLUENCES THE STRUCTURE OF THE ACTIVE SITE BUT IS NOT ESSENTIAL FOR ATP HYDROLYSIS

Structural highlights

1atr is a 1 chain structure with sequence from Bovin. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	, ,
Activity:	Adenosinetriphosphatase, with EC number 3.6.1.3
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[HSP7C_BOVIN] Acts as a repressor of transcriptional activation. Inhibits the transcriptional coactivator activity of CITED1 on Smad-mediated transcription. Chaperone. Component of the PRP19-CDC5L complex that forms an integral part of the spliceosome and is required for activating pre-mRNA splicing. May have a scaffolding role in the spliceosome assembly as it contacts all other components of the core complex (By similarity).

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

The chaperone protein Hsc70 is an ATPase of unknown mechanism, although the crystal structure of the 44-kDa ATPase domain has been solved. This structure shows that the hydroxyl of threonine 204 is located close to the gamma-phosphate of ATP, in a position where it might be an intermediate phosphate acceptor in the hydrolysis reaction. We made two point mutations at residue 204 of Hsc70, threonine to valine (T204V) and threonine to glutamic acid (T204E). The wild-type ATPase domain had a Km for ATP of approximately 1 microM; the mutants had Km values of approximately 90 microM. The kcat values for the mutant proteins were also increased. After crystallization, the structures of the T204V and T204E proteins were solved and refined with data to 2.3- and 2.4-A resolution, respectively. The overall tertiary structure of the mutants showed little change from the wild type; however, significant changes were observed in the active site. Analysis of the structures suggested possible reasons for the changes in kinetic constants. Threonine 204 does not seem to be an obligatory intermediate phosphate acceptor in the hydrolysis reaction since the mutants retained appreciable ATPase activity.

Threonine 204 of the chaperone protein Hsc70 influences the structure of the active site, but is not essential for ATP hydrolysis.,O'Brien MC, McKay DB J Biol Chem. 1993 Nov 15;268(32):24323-9. PMID:8226982^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ O'Brien MC, McKay DB. Threonine 204 of the chaperone protein Hsc70 influences the structure of the active site, but is not essential for ATP hydrolysis. J Biol Chem. 1993 Nov 15;268(32):24323-9. PMID:8226982