The genome of the square archaeon Haloquadratum walsbyi : life at the limits of water activity.
The genome of the square archaeon Haloquadratum walsbyi : life at the limits of water activity.
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方形古夸夸氏菌的基因组walsbyi：水活动极限的生命。
DOI：
10.1186/1471-2164-7-169
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发表时间：
2006-07-04
期刊：
影响因子：
4.4
通讯作者：
Oesterhelt, Dieter
中科院分区：
文献类型：
--
作者：
Bolhuis, Henk;Palm, Peter;Wende, Andy;Falb, Michaela;Rampp, Markus;Rodriguez-Valera, Francisco;Pfeiffer, Friedhelm;Oesterhelt, Dieter
方形嗜盐古菌Haloquadratum walsbyi在NaCl饱和和MgCl 2富集的水生生态系统中占主导地位，这对极低的水分活度造成了严重的干燥胁迫。通过基因组序列分析和生理物理实验，揭示了H。walsbyi专门研究了其狭窄和不利的生态位，并找到了科普干旱压力的方法。丰富的蛋白质库参与磷酸盐代谢，光合生长和细胞外保护聚合物，包括最大的古细菌蛋白质（9159个氨基酸），真核粘蛋白的同源物，是其中最突出的特点。相对较低的GC含量（47.9%），比其它嗜盐古菌低15-20%，是编码密度最低的古菌之一（76.5%）已知的原核生物可能是其独特环境的专业化的一个迹象，虽然没有发现直接的遗传指标，可以解释这种特殊的生物体如何保持其方形形状，基因组显示了几个独特的适应性特征，使这种生物能够在其特定和极端的生态位中茁壮成长。
The square halophilic archaeon Haloquadratum walsbyi dominates NaCl-saturated and MgCl2 enriched aquatic ecosystems, which imposes a serious desiccation stress, caused by the extremely low water activity. The genome sequence was analyzed and physiological and physical experiments were carried out in order to reveal how H. walsbyi has specialized into its narrow and hostile ecological niche and found ways to cope with the desiccation stress. A rich repertoire of proteins involved in phosphate metabolism, phototrophic growth and extracellular protective polymers, including the largest archaeal protein (9159 amino acids), a homolog to eukaryotic mucins, are amongst the most outstanding features. A relatively low GC content (47.9%), 15–20% less than in other halophilic archaea, and one of the lowest coding densities (76.5%) known for prokaryotes might be an indication for the specialization in its unique environment Although no direct genetic indication was found that can explain how this peculiar organism retains its square shape, the genome revealed several unique adaptive traits that allow this organism to thrive in its specific and extreme niche.