A nutrient uptake role for bacterial cell envelope extensions
A nutrient uptake role for bacterial cell envelope extensions
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DOI：
10.1073/pnas.0602047103
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发表时间：
2006-08-01
影响因子：
11.1
通讯作者：
Brun, Yves V.
中科院分区：
文献类型：
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作者：
Wagner, Jennifer K.;Setayeshgar, Sima;Brun, Yves V.
细菌以多种形态存在，但细胞形态与生物功能之间的关系仍然知之甚少。我们发现，新月柄杆菌细胞包膜的圆柱形延伸部分（假体）可以吸收并水解有机磷酸盐分子，并含有高亲和力磷酸盐结合蛋白 PstS，但不含有 PstA（一种将磷酸盐转运到细胞质中所需的蛋白质）。因此，磷酸盐源的吸收、水解和周质结合可以在茎中发生，但高亲和力输入必须在细胞体内发生。此外，通过使用分析模型，我们说明了茎的生物物理优势，作为对新月形藻繁衍生息的扩散限制、寡营养环境的形态适应。这一优点是由于茎又长又细，这是一种有利的形状，可以最大限度地与扩散的营养物质接触，同时最大限度地减少表面积和细胞体积的增加。
Bacteria exist in a variety of morphologies, but the relationship between cellular forms and biological functions remains poorly understood. We show that stalks (prosthecae), cylindrical extensions of the Caulobacter crescentus cell envelope, can take up and hydrolyze organic phosphate molecules and contain the high-affinity phosphate-binding protein PstS, but not PstA, a protein that is required for transport of phosphate into the cytoplasm. Therefore, uptake, hydrolysis, and periplasmic binding of a phosphate source can take place in the stalk, but high-affinity import must take place in the cell body. Furthermore, by using analytical modeling, we illustrate the biophysical advantage of the stalk as a morphological adaptation to the diffusion-limited, oligotrophic environments where C crescentus thrives. This advantage is due to the fact that a stalk is long and thin, a favorable shape for maximizing contact with diffusing nutrients while minimizing increases in both surface area and cell volume.