Activity of Bdellovibrio hit locus proteins, Bd0108 and Bd0109, links Type IVa pilus extrusion/retraction status to prey-independent growth signalling.
Activity of Bdellovibrio hit locus proteins, Bd0108 and Bd0109, links Type IVa pilus extrusion/retraction status to prey-independent growth signalling.
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DOI：
10.1371/journal.pone.0079759
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发表时间：
2013
期刊：
影响因子：
3.7
通讯作者：
Sockett RE
中科院分区：
文献类型：
--
作者：
Capeness MJ;Lambert C;Lovering AL;Till R;Uchida K;Chaudhuri R;Alderwick LJ;Lee DJ;Swarbreck D;Liddell S;Aizawa S;Sockett RE
噬菌蛭弧菌是生长在革兰氏阴性猎物体内的兼性捕食细菌，利用皮利侵入猎物的周质生态位。在经历了一个可逆的转变后，它们也可以在有机营养物上独立生长。生长转换机制的性质一直难以捉摸，但几个独立的报告表明，蛭弧菌基因组上的命中（宿主相互作用）位点的突变与过渡到不依赖猎物的生长有关。皮利是必不可少的猎物进入蛭弧菌和命中位点的序列分析预测，它是一组IVb型菌毛相关基因的一部分，包含bd 0108和bd 0109。在这项研究中，我们已经删除了整个bd 0108基因，这是独特的蛭弧菌，并比较其表型的菌株含有自发突变的bd 0108和常见的天然42 bp的缺失变体bd 0108。我们发现，整个bd 0108基因的缺失大大减少了皮利的挤出，而42 bp的缺失导致更大的菌毛挤出比野生型。从这些菌株中分离的皮利由IV a型菌毛蛋白; PilA组成。类似地删除基因bd 0109（其像bd 0108一样编码周质/分泌蛋白）的尝试没有成功，这表明它可能是蛭弧菌在任何生长模式中的生存力所必需的。Bd 0109具有糖结合YD-重复基序和具有推定的菌毛蛋白样折叠的N-末端，并且被发现与Bd 0108直接相互作用。这些结果使我们提出，Bd 0109/Bd 0108相互作用调节蛭弧菌菌毛的生产（可能通过与菌毛纤维在细胞壁的相互作用），菌毛的存在（和可能的收缩状态）反馈改变蛭弧菌细胞的生长状态。我们进一步确定了一种新的小RNA编码的命中位点，其转录在不同的bd 0108突变背景改变。
Bdellovibrio bacteriovorus are facultatively predatory bacteria that grow within gram-negative prey, using pili to invade their periplasmic niche. They also grow prey-independently on organic nutrients after undergoing a reversible switch. The nature of the growth switching mechanism has been elusive, but several independent reports suggested mutations in the hit (host-interaction) locus on the Bdellovibrio genome were associated with the transition to prey-independent growth. Pili are essential for prey entry by Bdellovibrio and sequence analysis of the hit locus predicted that it was part of a cluster of Type IVb pilus-associated genes, containing bd0108 and bd0109. In this study we have deleted the whole bd0108 gene, which is unique to Bdellovibrio, and compared its phenotype to strains containing spontaneous mutations in bd0108 and the common natural 42 bp deletion variant of bd0108. We find that deletion of the whole bd0108 gene greatly reduced the extrusion of pili, whereas the 42 bp deletion caused greater pilus extrusion than wild-type. The pili isolated from these strains were comprised of the Type IVa pilin protein; PilA. Attempts to similarly delete gene bd0109, which like bd0108 encodes a periplasmic/secreted protein, were not successful, suggesting that it is likely to be essential for Bdellovibrio viability in any growth mode. Bd0109 has a sugar binding YD- repeat motif and an N-terminus with a putative pilin-like fold and was found to interact directly with Bd0108. These results lead us to propose that the Bd0109/Bd0108 interaction regulates pilus production in Bdellovibrio (possibly by interaction with the pilus fibre at the cell wall), and that the presence (and possibly retraction state) of the pilus feeds back to alter the growth state of the Bdellovibrio cell. We further identify a novel small RNA encoded by the hit locus, the transcription of which is altered in different bd0108 mutation backgrounds.
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影响因子：
4.2
作者：
Lambert C;Till R;Hobley L;Sockett RE
通讯作者：
Sockett RE
影响因子：
6.7
作者：
Hobley L;Fung RK;Lambert C;Harris MA;Dabhi JM;King SS;Basford SM;Uchida K;Till R;Ahmad R;Aizawa S;Gomelsky M;Sockett RE
通讯作者：
Sockett RE
DOI：
10.1099/mic.0.050278-0
发表时间：
2011-10
期刊：
Microbiology (Reading, England)
影响因子：
--
作者：
Chaudhuri RR;Yu L;Kanji A;Perkins TT;Gardner PP;Choudhary J;Maskell DJ;Grant AJ
通讯作者：
Grant AJ
影响因子：
3.2
作者：
Evans, Katy J.;Lambert, Carey;Sockett, R. Elizabeth
通讯作者：
Sockett, R. Elizabeth
影响因子：
3.2
作者：
COTTER, TW;THOMASHOW, MF
通讯作者：
THOMASHOW, MF