Referenced in: none

Automatically associated channels: Kv10.1

Title: Genetic mapping of starch- and lambda-receptor sites in maltoporin: identification of substitutions causing direct and indirect effects on binding sites by cysteine mutagenesis.

Authors: G Francis, L Brennan, S Stretton, T Ferenci

Journal, date & volume: Mol. Microbiol., 1991 Sep , 5, 2293-301

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/1722561

Abstract
Cysteine mutagenesis was used to test the proximity of 16 residues to protein-ligand interaction sites in maltoporin (LamB protein). LamB protein with additional cysteines was incorporated into the outer membrane of Escherichia coli except with a Ser-30----Cys substitution. Phage Lambda and starch binding was assayed before and after incubation of mutants with six thiol-specific reagents. Four categories of mutation were recognized on the basis of phenotype and modification for each of the Lambda- and starch binding sites. The thiol modification experiments helped to clarify whether the phenotype of a mutation was due to a substitution at the binding site or an indirect perturbation of the structure. This study suggests that the cysteine mutagenesis/thiol modification approach may be usefully applied to the operational mapping of surface-accessible binding sites or epitopes.