title: The SGS3 protein involved in PTGS finds a family.
abstract: BACKGROUND
  Post transcriptional gene silencing (PTGS) is a recently discovered phenomenon that is an area of intense research interest. Components of the PTGS machinery are being discovered by genetic and bioinformatics approaches, but the picture is not yet complete.
  
  
  RESULTS
  The gene for the PTGS impaired Arabidopsis mutant sgs3 was recently cloned and was not found to have similarity to any other known protein. By a detailed analysis of the sequence of SGS3 we have defined three new protein domains: the XH domain, the XS domain and the zf-XS domain, that are shared with a large family of uncharacterised plant proteins. This work implicates these plant proteins in PTGS.
  
  
  CONCLUSIONS
  The enigmatic SGS3 protein has been found to contain two predicted domains in common with a family of plant proteins. The other members of this family have been predicted to be transcription factors, however this function seems unlikely based on this analysis. A bioinformatics approach has implicated a new family of plant proteins related to SGS3 as potential candidates for PTGS related functions.
authors.affiliation: The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridge, CB10 1SA, UK. agb@sanger.ac.uk
authors.forename: Alex
authors.initials: A
authors.lastname: Bateman
mesh_terms: D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins / Q000235:genetics*; D019295:Computational Biology / Q000379:methods; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics*; D010455:Peptides / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics; D034622:RNA Interference; D012323:RNA Processing, Post-Transcriptional; D018749:RNA, Plant / Q000378:metabolism*; D016415:Sequence Alignment / Q000379:methods; D017386:Sequence Homology, Amino Acid
chemical_list: D029681:Arabidopsis Proteins; D010455:Peptides; D018749:RNA, Plant; C410507:SGS3 protein, Arabidopsis