title: An evolutionarily conserved allosteric site modulates beta-lactamase activity.
abstract: Declining efficiency of antibiotic-inhibitor combinatorial therapies in treating beta-lactamase mediated resistance necessitates novel inhibitor development. Allosteric inhibition offers an alternative to conventional drugs that target the conserved active site. Here, we show that the evolutionarily conserved PWP triad located at the N-terminus of the H10 helix directly interacts with the allosteric site in TEM-1 beta-lactamase and regulates its activity. While point mutations in the PWP triad preserve the overall secondary structures around the allosteric site, they result in a more open and dynamic global structure with decreased chemical stability and increased aggregation propensity. These mutant enzymes with a less compact hydrophobic core around the allosteric site displayed significant activity loss. Detailed sequence and structure conservation analyses revealed that the PWP triad is an evolutionarily conserved motif unique to class A beta-lactamases aligning its allosteric site and hence is an effective potential target for enzyme regulation and selective drug design.
authors.affiliation: a Department of Bioengineering , Marmara University , İstanbul , Turkey.
authors.forename: Fatma Gizem
authors.initials: FG
authors.lastname: Avci
authors.affiliation: a Department of Bioengineering , Marmara University , İstanbul , Turkey.
authors.forename: Fatma Ece
authors.initials: FE
authors.lastname: Altinisik
authors.affiliation: b Department of Chemistry , Boston University , Boston , MA , USA , and.
authors.forename: Didem
authors.initials: D
authors.lastname: Vardar Ulu
authors.affiliation: c Department of Chemical Engineering , Bogazici University , İstanbul , Turkey.
authors.forename: Elif
authors.initials: E
authors.lastname: Ozkirimli Olmez
authors.affiliation: a Department of Bioengineering , Marmara University , İstanbul , Turkey.
authors.forename: Berna
authors.initials: B
authors.lastname: Sariyar Akbulut
mesh_terms: D000495:Allosteric Site / Q000187:drug effects; D020816:Amino Acid Motifs; D017124:Conserved Sequence; D015195:Drug Design; D004789:Enzyme Activation / Q000187:drug effects; D019143:Evolution, Molecular; D008958:Models, Molecular; D017354:Point Mutation; D014508:Urea / Q000494:pharmacology; D001618:beta-Lactamases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
chemical_list: D014508:Urea; D001618:beta-Lactamases
keywords: Allostery; PWP conservation; TEM-1; class A beta-lactamases; inhibition; structure function relationship