title: Genes for the peptidoglycan synthesis pathway are essential for chloroplast division in moss.
abstract: The general consensus is that a cyanobacterium phagocytosed by a host cell evolved into the plastids of red and green algae, land plants, and glaucophytes. In contrast to the plastids of glaucophytes, which retain a cyanobacterial-type peptidoglycan layer, no wall-like structures have been detected in plastids from other sources. Although the genome of Arabidopsis thaliana contains five genes that are essential for peptidoglycan synthesis, MurE, MurG, two genes for D-Ala-D-Ala ligase (Ddl), and the gene for translocase I (MraY), their functions have not been determined. We report that the moss Physcomitrella patens has nine homologous genes related to peptidoglycan biosynthesis: MurA, B, C, D, E, and F, Ddl, genes for the penicillin-binding protein Pbp, and dd-carboxypeptidase (Dac). Corroborating a computer prediction, analysis of the GFP fusion proteins with the N terminus of PpMurE or of PpPbp suggests that these proteins are located in the chloroplasts. Gene disruption of the PpMurE gene in P. patens resulted in the appearance of macrochloroplasts both in protonema and in leaf cells. Moreover, gene knockout of the P. patens Pbp gene showed inhibition of chloroplast division in this moss; however, no Pbp gene was found in A. thaliana.
authors.affiliation: Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan.
authors.forename: Mariko
authors.initials: M
authors.lastname: Machida
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Takechi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sato
authors.forename: Sung Jin
authors.initials: SJ
authors.lastname: Chung
authors.forename: Haruko
authors.initials: H
authors.lastname: Kuroiwa
authors.forename: Susumu
authors.initials: S
authors.lastname: Takio
authors.forename: Motoaki
authors.initials: M
authors.lastname: Seki
authors.forename: Kazuo
authors.initials: K
authors.lastname: Shinozaki
authors.forename: Tomomichi
authors.initials: T
authors.lastname: Fujita
authors.forename: Mitsuyasu
authors.initials: M
authors.lastname: Hasebe
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Takano
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D001483:Base Sequence; D019068:Bryopsida / Q000235:genetics* / Q000378:metabolism* / Q000648:ultrastructure; D002736:Chloroplasts / Q000235:genetics* / Q000378:metabolism*; D018744:DNA, Plant / Q000235:genetics; D019143:Evolution, Molecular; D017343:Genes, Plant; D008854:Microscopy, Electron; D008969:Molecular Sequence Data; D010457:Peptidoglycan / Q000096:biosynthesis* / Q000235:genetics*
chemical_list: D018744:DNA, Plant; D010457:Peptidoglycan