4rla
From Proteopedia
| |||||||
| , resolution 2.94Å | |||||||
|---|---|---|---|---|---|---|---|
| Sites: | , and | ||||||
| Ligands: | |||||||
| Gene: | PARGR-2 (Rattus norvegicus) | ||||||
| Activity: | Arginase, with EC number 3.5.3.1 | ||||||
| Coordinates: | save as pdb, mmCIF, xml | ||||||
ALTERING THE BINUCLEAR MANGANESE CLUSTER OF ARGINASE DIMINISHES THERMOSTABILITY AND CATALYTIC FUNCTION
Overview
Arginase is a thermostable (Tm = 75 degrees C) binuclear manganese metalloenzyme which hydrolyzes l-arginine to form l-ornithine and urea. The three-dimensional structures of native metal-depleted arginase, metal-loaded H101N arginase, and metal-depleted H101N arginase have been determined by X-ray crystallographic methods to probe the roles of the manganese ion in site A (Mn2+A) and its ligand H101 in catalysis and thermostability. We correlate these structures with thermal stability and catalytic activity measurements reported here and elsewhere [Cavalli, R. C., Burke, C. J., Kawamoto, S., Soprano, D. R., and Ash, D. E. (1994) Biochemistry 33, 10652-10657]. We conclude that the substitution of a wild-type histidine ligand to Mn2+A compromises metal binding, which in turn compromises protein thermostability and catalytic function. Therefore, a fully occupied binuclear manganese metal cluster is required for optimal catalysis and thermostability.
About this Structure
4RLA is a Single protein structure of sequence from Rattus norvegicus. Full crystallographic information is available from OCA.
Reference
Altering the binuclear manganese cluster of arginase diminishes thermostability and catalytic function., Scolnick LR, Kanyo ZF, Cavalli RC, Ash DE, Christianson DW, Biochemistry. 1997 Aug 26;36(34):10558-65. PMID:9265637
Page seeded by OCA on Thu Mar 20 19:10:50 2008
