title: Complete genome structure of Gloeobacter violaceus PCC 7421, a cyanobacterium that lacks thylakoids.
abstract: The nucleotide sequence of the entire genome of a cyanobacterium Gloeobacter violaceus PCC 7421 was determined. The genome of G. violaceus was a single circular chromosome 4,659,019 bp long with an average GC content of 62%. No plasmid was detected. The chromosome comprises 4430 potential protein-encoding genes, one set of rRNA genes, 45 tRNA genes representing 44 tRNA species and genes for tmRNA, B subunit of RNase P, SRP RNA and 6Sa RNA. Forty-one percent of the potential protein-encoding genes showed sequence similarity to genes of known function, 37% to hypothetical genes, and the remaining 22% had no apparent similarity to reported genes. Comparison of the assigned gene components with those of other cyanobacteria has unveiled distinctive features of the G. violaceus genome. Genes for PsaI, PsaJ, PsaK, and PsaX for Photosystem I and PsbY, PsbZ and Psb27 for Photosystem II were missing, and those for PsaF, PsbO, PsbU, and PsbV were poorly conserved. cpcG for a rod core linker peptide for phycobilisomes and nblA related to the degradation of phycobilisomes were also missing. Potential signal peptides of the presumptive products of petJ and petE for soluble electron transfer catalysts were less conserved than the remaining portions. These observations may be related to the fact that photosynthesis in G. violaceus takes place not in thylakoid membranes but in the cytoplasmic membrane. A large number of genes for sigma factors and transcription factors in the LuxR, LysR, PadR, TetR, and MarR families could be identified, while those for major elements for circadian clock, kaiABC were not found. These differences may reflect the phylogenetic distance between G. violaceus and other cyanobacteria.
authors: Kazusa DNA Research Institute, 2-6-7 Kazusa-kamatari, Kisarazu, Chiba 292-0818, Japan.
authors: Yasukazu
authors: Y
authors: Nakamura
authors: Takakazu
authors: T
authors: Kaneko
authors: Shusei
authors: S
authors: Sato
authors: Mamoru
authors: M
authors: Mimuro
authors: Hideaki
authors: H
authors: Miyashita
authors: Tohru
authors: T
authors: Tsuchiya
authors: Shigemi
authors: S
authors: Sasamoto
authors: Akiko
authors: A
authors: Watanabe
authors: Kumiko
authors: K
authors: Kawashima
authors: Yoshie
authors: Y
authors: Kishida
authors: Chiaki
authors: C
authors: Kiyokawa
authors: Mitsuyo
authors: M
authors: Kohara
authors: Midori
authors: M
authors: Matsumoto
authors: Ai
authors: A
authors: Matsuno
authors: Naomi
authors: N
authors: Nakazaki
authors: Sayaka
authors: S
authors: Shimpo
authors: Chie
authors: C
authors: Takeuchi
authors: Manabu
authors: M
authors: Yamada
authors: Satoshi
authors: S
authors: Tabata
mesh_terms: D001483:Base Sequence; D000458:Cyanobacteria / Q000235:genetics*; D005798:Genes, Bacterial / Q000502:physiology*; D016680:Genome, Bacterial; D008969:Molecular Sequence Data; D010788:Photosynthesis; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA; D017385:Sequence Homology; D015398:Signal Transduction; D020524:Thylakoids / Q000235:genetics / Q000502:physiology*