title: Identification and analysis of polyserine linker domains in prokaryotic proteins with emphasis on the marine bacterium Microbulbifer degradans.
abstract: Polyserine linkers (PSLs) are interdomain, serine-rich sequences found in modular proteins. Though common among eukaryotes, their presence in prokaryotic enzymes is limited. We identified 46 extracellular proteins involved in complex carbohydrate degradation from Microbulbifer degradans that contain PSLs that separate carbohydrate-binding domains or catalytic domains from other binding domains. In nine M. degradans proteins, PSLs also separated amino-terminal lipoprotein acylation sites from the remainder of the polypeptide. Furthermore, among the 76 PSL proteins identified in sequence repositories, 65 are annotated as proteins involved in complex carbohydrate degradation. We discuss the notion that PSLs are flexible, disordered spacer regions that enhance substrate accessibility.
authors.affiliation: Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland 20742, USA.
authors.forename: Michael B
authors.initials: MB
authors.lastname: Howard
authors.forename: Nathan A
authors.initials: NA
authors.lastname: Ekborg
authors.forename: Larry E
authors.initials: LE
authors.lastname: Taylor
authors.forename: Steven W
authors.initials: SW
authors.lastname: Hutcheson
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Weiner
mesh_terms: D034241:Alteromonadaceae / Q000201:enzymology* / Q000235:genetics; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics; D002480:Cellulase / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D009792:Oceans and Seas; D010455:Peptides / Q000737:chemistry* / Q000235:genetics; D017434:Protein Structure, Tertiary
chemical_list: D001426:Bacterial Proteins; D010455:Peptides; C027794:polyserine; D002480:Cellulase