Association of Lanthipeptide Genes with TnpAREP Transposases in Marine Picocyanobacteria
Association of Lanthipeptide Genes with TnpAREP Transposases in Marine Picocyanobacteria
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海洋微微蓝藻中 Lanthipeptide 基因与 TnpAREP 转座酶的关联
DOI：
10.1101/2020.03.09.984088
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Chisholm, SW
中科院分区：
文献类型：
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作者：
Laurenceau, R.;Raho, N;Cariani, Z;Bliem, C;Osman, M;Chisholm, SW
兰西肽是一类核糖体合成的、翻译后修饰的肽，广泛存在于细菌中，通常起到抗菌作用。海洋微微蓝细菌原绿球藻和聚球藻产生一组不寻常且多样化的功能未知的羊毛硫肽，称为原氯绿素。虽然经过充分研究的模型细菌可以产生一到两种不同的这种类型的分子，但单个微微蓝细菌可以产生多达 80 个；一毫升海水中的微微蓝藻群落可以共同编码多达 10,000 个原氯素。导致微微蓝细菌（海洋中数量占优势的光合细菌）中羊毛硫肽库的扩展和多样化的分子事件尚不清楚。我们提供了原绿素基因与属于 TnpAREP 家族的单链 DNA 转座酶之间不寻常关联的证据。这些基因在海洋微微蓝细菌的系统发育中共同出现和共同定位，在基因组内形成独特的关联模式，很可能是由转座酶活性引起的。考虑到 TnpAREPhomologs 在其他细菌中的作用，我们基于基因组结构提出，它们通过多样化的重组机制有助于创造原氯素结构多样性。提交后说明自从最初将这篇手稿提交给 bioRxiv 以来，我们已经完善了对 TnpA-REP 转座酶的系统发育分析，并且我们没有找到支持或反对 TnpA-REP 存在之间因果关系的有力证据转座酶以及羊毛硫肽基因的扩展和多样化。虽然手稿中描述的遗传关联仍然有效，但相邻的 TnpA-REP 和原氯绿素似乎没有系统发育联系，这可能只是两个基因高重组率的结果。需要更多的基因组数据来阐明海洋微微蓝细菌中羊毛硫肽基因扩增背后的驱动力。重要性仅描述了几种促进细菌中靶基因区域多样化的机制。我们提供了间接证据，表明与微微蓝细菌中原氯红素相关的 TnpAREP 转座酶可能代表了一种新的机制，并解释了这种丰富的海洋微生物中原氯红素的极端扩展和多样化。
Lanthipeptides are a family of ribosomally synthesized, post-translationally modified peptides that are widespread among bacteria, typically functioning as antibacterials. The marine picocyanobacteriaProchlorococcusandSynechococcusproduce an unusual and diverse set of lanthipeptides of unknown function called prochlorosins. While well-studied model bacteria produce one or two different molecules of this type, a single picocyanobacterium can produce as many as 80; the community of picocyanobacteria in a single milliliter of seawater can collectively encode up to 10,000 prochlorosins. The molecular events that led to this expansion and diversification of the lanthipeptide repertoire in picocyanobacteria – the numerically dominant photosynthesizers in the oceans – is unknown.We present evidence for an unusual association between prochlorosin genes with a single-stranded DNA transposase belonging to the TnpAREPfamily. The genes co-occur and co-localize across the phylogeny of marine picocyanobacteria forming a distinct association pattern within genomes, most likely resulting from the transposase activity. Given the role of TnpAREPhomologs in other bacteria, we propose - based on genomic structures - that they contribute to the creation of the prochlorosin structural diversity through a diversifying recombination mechanism.Post-submission noteSince the original submission of this manuscript to bioRxiv, we have refined our phylogenetic analysis of the TnpA-REP transposases and we do not find strong evidence for or against a causal relationship between the presence of TnpA-REP transposases and the expansion and diversification of lanthipeptides genes. While the genetic association described in the manuscript remains valid, adjacent TnpA-REP and Prochlorosins do not appear phylogenetically linked, which might simply be the consequence of high rates of recombination for both genes. More genomic data are needed to untangle the driving force behind the lanthipeptide gene expansion in marine picocyanobacteria.IMPORTANCEOnly a few mechanisms have been described that promote the diversification of a targeted gene region in bacteria. We present indirect evidence that the TnpAREPtransposases associated with prochlorosins in picocyanobacteria could represent a novel such mechanism, and explain the extreme expansion and diversification of prochlorosins in this abundant marine microbe.