Genes for the peptidoglycan synthesis pathway are essential for chloroplast division in moss
Genes for the peptidoglycan synthesis pathway are essential for chloroplast division in moss
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DOI：
10.1073/pnas.0510693103
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发表时间：
2006-04-25
影响因子：
11.1
通讯作者：
Takano, H
中科院分区：
文献类型：
--
作者：
Machida, M;Takechi, K;Takano, H
一般的共识是，蓝藻被宿主细胞吞噬后进化成红藻和绿色藻类、陆生植物和蓝绿藻的质体。与保留蓝藻型肽聚糖层的蓝绿藻质体相反，在其他来源的质体中没有检测到壁样结构。虽然拟南芥的基因组包含五个对肽聚糖合成至关重要的基因，MurE、MurG、两个D-Ala-D-Ala连接酶基因（Ddl）和转位酶I基因（MraY），但它们的功能尚未确定。本文报道了藓类小立碗藓（Physcomitrella patens）中与肽聚糖生物合成相关的9个同源基因：MurA、B、C、D、E、F、Ddl、青霉素结合蛋白Pbp基因和DD-羧肽酶（Dac）基因。证实了计算机的预测，分析的GFP融合蛋白的N末端的PpMurE或PpPbp表明，这些蛋白质位于叶绿体。PpMurE基因的基因破坏导致在原丝体和叶细胞中都出现大叶绿体。此外，Pbp基因的敲除也抑制了该藓类植物的叶绿体分裂，而在A. patens中没有发现Pbp基因。thaliana。
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. thalliana.