title: The AlnB protein of the bioemulsan alasan is a peroxiredoxin.
abstract: The bioemulsifier of Acinetobacter radioresistens KA53, referred to as alasan, is a high molecular weight complex of a polysaccharide and three proteins (AlnA, AlnB and AlnC). AlnA has previously been shown to be an OmpA-like protein that is largely responsible for the emulsifying activity of alasan. To further elucidate the nature of alasan, the gene coding for AlnB was cloned, sequenced and overexpressed in Escherichia coli. The overall 561 bp sequence of the hypothetical AlnB showed strong homology, including all conserved regions and residues known to be essential for enzymatic activity, to the ubiquitous family of thiol-specific antioxidant enzymes known as peroxiredoxins. Transgenic E. coli overexpressing AlnB exhibited increased resistance to cumene hydroperoxide both in liquid culture and on agar medium. Recombinant AlnB had no emulsifying activity but stabilized oil-in-water emulsion generated by AlnA.
authors.affiliation: Department of Molecular Microbiology & Biotechnology, Tel Aviv University, Ramat Aviv, 69978, Israel.
authors.forename: R
authors.initials: R
authors.lastname: Bekerman
authors.forename: G
authors.initials: G
authors.lastname: Segal
authors.forename: E Z
authors.initials: EZ
authors.lastname: Ron
authors.forename: E
authors.initials: E
authors.lastname: Rosenberg
mesh_terms: D000150:Acinetobacter / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry*; D003001:Cloning, Molecular; D045703:Emulsifying Agents / Q000737:chemistry; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005079:Excipients / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D010544:Peroxidases / Q000737:chemistry* / Q000378:metabolism; D054464:Peroxiredoxins; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D011994:Recombinant Proteins / Q000096:biosynthesis
chemical_list: D001426:Bacterial Proteins; D045703:Emulsifying Agents; D005079:Excipients; D011135:Polysaccharides, Bacterial; D011994:Recombinant Proteins; C443985:alasan protein, Acinetobacter radioresistens; D010544:Peroxidases; D054464:Peroxiredoxins