1vcv
From Proteopedia
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Structure of 2-deoxyribose-5-phosphate aldolase from Pyrobaculum aerophilum
Overview
Genes encoding 2-deoxy-d-ribose-5-phosphate aldolase (DERA) homologues, from two hyperthermophiles, the archaeon Pyrobaculum aerophilum and the, bacterium Thermotoga maritima, were expressed individually in Escherichia, coli, after which the structures and activities of the enzymes produced, were characterized and compared with those of E. coli DERA. To our, surprise, the two hyperthermophilic DERAs showed much greater catalysis of, sequential aldol condensation using three acetaldehydes as substrates than, the E. coli enzyme, even at a low temperature (25 degrees C), although, both enzymes showed much less 2-deoxy-d-ribose-5-phosphate synthetic, activity. Both the enzymes were highly resistant to high concentrations of, acetaldehyde and retained about 50% of their initial activities after a, 20-h exposure to 300 mM acetaldehyde at 25 degrees C, whereas the E. coli, DERA was almost completely inactivated after a 2-h exposure under the same, conditions. The structure of the P. aerophilum DERA was determined by, X-ray crystallography to a resolution of 2.0 A. The main chain coordinate, of the P. aerophilum enzyme monomer was quite similar to those of the T., maritima and E. coli enzymes, whose crystal structures have already been, solved. However, the quaternary structure of the hyperthermophilic enzymes, was totally different from that of the E. coli DERA. The areas of the, subunit-subunit interface in the dimer of the hyperthermophilic enzymes, are much larger than that of the E. coli enzyme. This promotes the, formation of the unique dimeric structure and strengthens the hydrophobic, intersubunit interactions. These structural features are considered, responsible for the extremely high stability of the hyperthermophilic, DERAs.
About this Structure
1VCV is a Single protein structure of sequence from Pyrobaculum aerophilum with as ligand. Active as Deoxyribose-phosphate aldolase, with EC number 4.1.2.4 Full crystallographic information is available from OCA.
Reference
Sequential aldol condensation catalyzed by hyperthermophilic 2-deoxy-d-ribose-5-phosphate aldolase., Sakuraba H, Yoneda K, Yoshihara K, Satoh K, Kawakami R, Uto Y, Tsuge H, Takahashi K, Hori H, Ohshima T, Appl Environ Microbiol. 2007 Nov;73(22):7427-34. Epub 2007 Sep 28. PMID:17905878
Page seeded by OCA on Wed Jan 23 11:21:48 2008
