Structure of yeast inorganic pyrophosphatase: Refinement
- Oak Ridge National Lab., TN (United States)
- Univ. of Pennsylvania, Philadelphia (United States)
Yeast inorganic pyrophosphatase, PPase, is a dimeric enzyme (64kD) of chemically identical subunits consisting of 285 amino acids. It catalyzes the hydrolysis of pyrophosphate to orthophosphate and is therefore essential in the energy utilization of all life forms. PPase crystallizes in the monoclinic space group P2{sub 1} with cell dimensions of a = 69.96, b = 95.27, c = 51.77 {angstrom}, {beta} = 99.5{degree} and a dimer in the asymmetric unit. Data up to 2.3{angstrom} resolution were collected at {minus}50C by rotation photography, optically scanned and processed. Coordinates of a 3{angstrom} resolution study of PPase at room temperature were taken from the Brookhaven Protein Data Bank and used to initiate refinement with a starting R-factor of 52%. The refinement proceeded smoothly using the program PROLSQ installed on a Cray-2, and from 2F{sub o}-F{sub c} maps the missing terminal amino acids were eventually fitted on a PS350 graphics system. Some corrections were made to the backbone and numerous side-chains were also readjusted. The intermediate R-factor is 28% with solvent water presently being incorporated into the structure.
- OSTI ID:
- 5312130
- Report Number(s):
- CONF-9104107-; CODEN: FAJOE
- Journal Information:
- FASEB Journal (Federation of American Societies for Experimental Biology); (United States), Vol. 5:4; Conference: 75. annual meeting of the Federation of American Societies for Experimental Biology (FASEB), Atlanta, GA (United States), 21-25 Apr 1991; ISSN 0892-6638
- Country of Publication:
- United States
- Language:
- English
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