title: Slr0006-like proteins: A TsaC/TsaC2/YciO subfamily exclusive to cyanobacteria.
abstract: The universally conserved TsaC/TsaC2/YciO family of proteins is essential for the N6-threonylcarbamoyladenosine modification present in almost all ANN-decoding tRNAs. Previously, the family has been grouped into the TsaC/TsaC2 and YciO subfamilies. We used sequence analysis, phylogenetic methods and homology modeling to show that a third subfamily, the Slr0006-like subfamily, exists exclusively in some cyanobacteria. The Slr0006-like proteins are solely found together with both TsaC and YciO homologs, indicating a distinct function for the Slr0006-like subfamily. Accordingly, the homology models show that the amino acids in their putative binding clefts differ significantly. Hence, we introduce a new cyanobacterial subfamily of proteins with the TsaC-domain fold, along with the generated classification rules to assign new members to the correct cyanobacterial subfamily.
authors.affiliation: Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Tykistökatu 6A, 20520 Turku, Finland.
authors.forename: Leonor L
authors.initials: LL
authors.lastname: Carvalho
authors.affiliation: Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Tykistökatu 6A, 20520 Turku, Finland.
authors.forename: Tiina A
authors.initials: TA
authors.lastname: Salminen
authors.affiliation: Structural Bioinformatics Laboratory, Biochemistry, Faculty of Science and Engineering, Åbo Akademi University, Tykistökatu 6A, 20520 Turku, Finland. Electronic address: kathe.dahlstrom@abo.fi.
authors.forename: Käthe M
authors.initials: KM
authors.lastname: Dahlström
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000145:classification / Q000235:genetics; D001665:Binding Sites; D017124:Conserved Sequence; D019143:Evolution, Molecular; D056004:Molecular Dynamics Simulation; D058977:Molecular Sequence Annotation; D008969:Molecular Sequence Data; D010802:Phylogeny; D000072417:Protein Domains; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D040681:Structural Homology, Protein; D046939:Synechocystis / Q000235:genetics*
chemical_list: D001426:Bacterial Proteins
keywords: Homology modeling; Protein evolution; Sll0216; Sll1866; tRNA modification