title: In silico prediction of potential metallothioneins and metallohistins in actinobacteria.
abstract: Metallothioneins and metallohistins are short peptides with a high cysteine and/or histidine content able to coordinate metals intracellularly, thereby increasing the tolerance against elevated concentrations of metals. Because of their features, they can be detected by in silico prediction from proteomes annotated from sequenced genomes. Here, we analyzed 73 sequenced actinobacterial genomes for peptides (≤ 100 amino acids) with a high content of cysteine and histidine (≥ 15%) and identified 103 putative metallothioneins and metallohistins. For 45 of these peptides, we found similarities to metal binding protein domains, including zinc fingers, heavy metal transporters or eukaryotic metallothioneins, which can serve as proof-of-principle in underscoring a potential function as metal binding peptides. An evolutionary origin from metal containing domains of enzymes is discussed and metallohistins not containing cysteine are described for the first time for bacteria.
authors.affiliation: Microbial Phytopathology, Institute of Microbiology, Faculty of Biology and Pharmacy, Friedrich-Schiller-University, Jena, Germany.
authors.forename: Andre
authors.initials: A
authors.lastname: Schmidt
authors.forename: Matthias
authors.initials: M
authors.lastname: Hagen
authors.forename: Eileen
authors.initials: E
authors.lastname: Schütze
authors.forename: Astrid
authors.initials: A
authors.lastname: Schmidt
authors.forename: Erika
authors.initials: E
authors.lastname: Kothe
mesh_terms: D039903:Actinobacteria / Q000187:drug effects / Q000235:genetics*; D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D016000:Cluster Analysis; D019295:Computational Biology / Q000379:methods; D024881:Drug Resistance, Bacterial; D019143:Evolution, Molecular; D008668:Metallothionein / Q000235:genetics* / Q000378:metabolism; D019216:Metals, Heavy / Q000633:toxicity; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid
chemical_list: D019216:Metals, Heavy; D008668:Metallothionein