Naslov
Nonribosomal peptide synthetases-evidence for a second ATP-binding site

Autori
Kallow, W ; Pavela-Vrančič, M ; Dieckmann, R ; von Dohren, H

Izvornik
Biochimica et biophysica acta. Proteins and proteomics (1570-9639) 1601 (2002), 1; 93-99

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Acv synthetase; Aminoacyl adenylation; Substrate inhibition

Sažetak
Delta-(L-alpha-Aminoadipyl)-L-eysteinyl-D-valine synthetase (ACVS) catalyses, via the protein thiotemplate mechanism, the nonribosomal biosynthesis of the penicillin and cephalosporin precursor tripeptide delta-(L-alpha-aminoadipyl)-L-cysteinyl-D-valine (ACV). The complete and fully saturated biosynthetic system approaches maximum rate of product generation with increasing ATP concentration. Nonproductive adenylation of ACVS, monitored utilising the ATP-[P-32]PPi exchange reaction, has revealed substrate inhibition with ATP. The kinetic inhibition pattern provides evidence for the existence of a second nucleotide-binding site with possible implication in the regulatory mechanism. Under suboptimal reaction conditions, in the presence of MgATP(2-), L-Cys and inorganic pyrophosphatase, ACVS forms adenosine(5')tetraphospho(5')adenosine (Ap(4)A) from the reverse reaction of adenylate formation involving a second ATP molecule. The potential location of the second ATP binding site was deduced from sequence comparisons and molecular visualisation in conjunction to data obtained from biochemical analysis.

Izvorni jezik
Engleski

Znanstvena područja
Biologija

POVEZANOST RADA