title: Nucleotide sequence of the Spiroplasma citri fibril protein gene.
abstract: Electron microscopic observation of spiroplasmas lysed by detergent (sodium deoxycholate) revealed the release of bundles of fibrils from the cells. Individual fibrils are 4 nm in diameter and possess a 9-nm periodicity along their length. These fibrils are thought to function as cytoskeletal structures involved in the shape and motility of spiroplasmas. Polyacrylamide gel electrophoresis of density gradient-purified fibrils showed a protein of approximately 55 kDa. Oligonucleotide probes were constructed from the N-terminal amino acid sequence of two peptides obtained after V8 protease hydrolysis of the fibril protein. The probes were used to identify the clones in a genomic DNA library of Spiroplasma citri that contained inserts carrying the probe sequence. Sequencing of a 3.3-kbp fragment yielded the full open reading frame of the fibril protein gene and the start of a second open reading frame of an unknown protein. The fibril protein is composed of 515 amino acids, which have a computed molecular mass of 59 kDa. Northern (RNA) blot hybridization and primer extension experiments showed that transcription of the fibril protein gene starts from a promoter located 100 nucleotides upstream of the initiation codon and stops at a rho-independent type terminator, leading to a 1.7-kbp transcript. Southern blot hybridization of genomic DNA using the fibril protein gene as the probe showed that a single copy of the gene is present in the chromosomes of both S. citri and Spiroplasma melliferum. The genotypic symbol fib is proposed for the spiroplasma fibril protein gene.
authors.affiliation: Department of Anatomical Sciences, State University of New York, Stony Brook 11794-8081.
authors.forename: D L
authors.initials: DL
authors.lastname: Williamson
authors.forename: J
authors.initials: J
authors.lastname: Renaudin
authors.forename: J M
authors.initials: JM
authors.lastname: Bové
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D003001:Cloning, Molecular; D003062:Codon / Q000235:genetics; D003598:Cytoskeletal Proteins / Q000032:analysis / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D005798:Genes, Bacterial; D015698:Genomic Library; D008969:Molecular Sequence Data; D015345:Oligonucleotide Probes; D011487:Protein Conformation; D012329:RNA, Bacterial / Q000235:genetics / Q000302:isolation & purification; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D013149:Spiroplasma / Q000235:genetics* / Q000648:ultrastructure
chemical_list: D001426:Bacterial Proteins; D003062:Codon; D003598:Cytoskeletal Proteins; D004269:DNA, Bacterial; D015345:Oligonucleotide Probes; D012329:RNA, Bacterial; C069778:fibril protein, Spiroplasma citri