Please use this identifier to cite or link to this item: https://doi.org/10.1016/S0378-1097(99)00445-0
Title: Site-directed mutagenesis of arginine-89 supports the role of its guanidino side-chain in substrate binding by Cephalosporium acremonium isopenicillin N synthase
Authors: Loke, P. 
Sim, T.-S. 
Keywords: Cephalosporium acremonium
Isopenicillin N synthase
Site-directed mutagenesis
Substrate binding
Issue Date: 1999
Source: Loke, P., Sim, T.-S. (1999). Site-directed mutagenesis of arginine-89 supports the role of its guanidino side-chain in substrate binding by Cephalosporium acremonium isopenicillin N synthase. FEMS Microbiology Letters 179 (2) : 423-429. ScholarBank@NUS Repository. https://doi.org/10.1016/S0378-1097(99)00445-0
Abstract: Isopenicillin N synthase (IPNS) catalyses a key step in the penicillin and cephalosporin biosynthetic pathway which involves the oxidative cyclisation of the acyclic peptide δ-(L-α-aminoadipyl)-L-cysteinyl-D-valine (ACV) to isopenicillin N. Based on crystallographic evidence from the Aspergillus nidulans IPNS crystal structure complexed with the substrate ACV (Roach et al. (1997) Nature 387, 827-830), we were able to provide mutational evidence for the critical involvement of the conserved R-X-S motif in ACV binding in IPNS. The crystal structure further implicated arginine-87 in the binding of the aminoadipyl portion of ACV. Thus, in this study, the site-directed mutagenesis of the corresponding arginine-89 in Cephalosporium acremonium IPNS (cIPNS) was performed to ascertain its role in cIPNS. Alteration of arginine-89 to five amino acids from different amino acid groups, namely lysine, serine, alanine, aspartate and leucine, was performed and no activity was detected in all the mutants obtained when enzyme bioassays were performed. Furthermore, the solubility of the mutants was considerably lower than the wild-type cIPNS after expression at 37°C, but could be recovered when the expression temperature was lowered to 25°C. This suggests that arginine-89 could be critical for the activity of cIPNS due to its involvement in ACV binding and the solubility of wild-type enzyme. Copyright (C) 1999 Federation of European Microbiological Societies.
Source Title: FEMS Microbiology Letters
URI: http://scholarbank.nus.edu.sg/handle/10635/31170
ISSN: 03781097
DOI: 10.1016/S0378-1097(99)00445-0
Appears in Collections:Staff Publications

Show full item record
Files in This Item:
There are no files associated with this item.

SCOPUSTM   
Citations

6
checked on Jan 17, 2018

WEB OF SCIENCETM
Citations

6
checked on Jan 17, 2018

Page view(s)

145
checked on Jan 12, 2018

Google ScholarTM

Check

Altmetric


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.