title: Cysteine usage in Sulfolobus spindle-shaped virus 1 and extension to hyperthermophilic viruses in general.
abstract: Fuselloviridae are ubiquitous crenarchaeal viruses found in high-temperature acidic hot springs worldwide. The type virus, Sulfolobus spindle-shaped virus 1 (SSV1), has a double-stranded DNA genome that contains 34 open reading frames (ORFs). Fuselloviral genomes show little similarity to other organisms, generally precluding functional predictions. However, tertiary protein structure can provide insight into protein function. We have thus undertaken a systematic investigation of the SSV1 proteome and report here on the F112 gene product. Biochemical, proteomic and structural studies reveal a monomeric intracellular protein that adopts a winged helix DNA binding fold. Notably, the structure contains an intrachain disulfide bond, prompting analysis of cysteine usage in this and other hyperthermophilic viral genomes. The analysis supports a general abundance of disulfide bonds in the intracellular proteins of hyperthermophilic viruses, and reveals decreased cysteine content in the membrane proteins of hyperthermophilic viruses infecting Sulfolobales. The evolutionary implications of the SSV1 distribution are discussed.
authors.affiliation: Thermal Biology Institute, Montana State University, Bozeman, MT 59717, USA.
authors.forename: Smita K
authors.initials: SK
authors.lastname: Menon
authors.forename: Walid S
authors.initials: WS
authors.lastname: Maaty
authors.forename: G Judson
authors.initials: GJ
authors.lastname: Corn
authors.forename: Stanley C
authors.initials: SC
authors.lastname: Kwok
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Eilers
authors.forename: Paul
authors.initials: P
authors.lastname: Kraft
authors.forename: Eric
authors.initials: E
authors.lastname: Gillitzer
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Young
authors.forename: Brian
authors.initials: B
authors.lastname: Bothner
authors.forename: C Martin
authors.initials: CM
authors.lastname: Lawrence
mesh_terms: D003545:Cysteine / Q000032:analysis / Q000378:metabolism*; D004220:Disulfides / Q000032:analysis; D019241:Fuselloviridae / Q000737:chemistry* / Q000235:genetics; D016679:Genome, Viral; D019077:Helix-Turn-Helix Motifs; D045482:Hot Springs / Q000382:microbiology; D008958:Models, Molecular; D016366:Open Reading Frames / Q000235:genetics; D020543:Proteome / Q000378:metabolism; D016944:Sulfolobus / Q000821:virology*; D014764:Viral Proteins / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism; D014871:Water Microbiology
chemical_list: D004220:Disulfides; D020543:Proteome; D014764:Viral Proteins; D003545:Cysteine