Evidence for feedback (trans) regulation of, and two systems for, glycine betaine transport by Staphylococcus aureus.
Evidence for feedback (trans) regulation of, and two systems for, glycine betaine transport by Staphylococcus aureus.
复制标题
金黄色葡萄球菌对甘氨酸甜菜碱转运的反馈（反式）调节和两个系统的证据。
DOI：
10.1099/13500872-140-11-3139
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发表时间：
1994
期刊：
影响因子：
--
通讯作者：
Wilkinson,BJ
中科院分区：
文献类型：
--
作者：
Stimeling,KW;Graham,JE;Kaenjak,A;Wilkinson,BJ
以往的报道对葡萄球菌中甘氨酸甜菜碱转运系统的数目存在争议，在复合培养基中生长的葡萄球菌表现出一个中等亲和力的单一转运系统。在不存在甘氨酸甜菜碱的情况下在限定培养基中生长的细胞显示出高亲和力和低亲和力转运系统。细胞生长在甘氨酸甜菜碱的存在下，在存在的渗透胁迫下，在复杂的或确定的媒体积累了大量的内部甘氨酸甜菜碱。较小的，但仍然显着的，甘氨酸甜菜碱的量积累的细胞生长在其存在下，无论是复杂的或确定的媒体在没有渗透胁迫。在存在或不存在渗透胁迫的情况下，在存在甘氨酸甜菜碱的情况下，在成分确定的培养基中生长的细胞显示出比在其不存在下生长的细胞更低的甘氨酸甜菜碱转运速率。这表明甘氨酸甜菜碱转运受到反馈或内部甘氨酸甜菜碱的反式抑制。这可以解释在复合或确定成分培养基中生长的细胞中观察到的动力学差异，高亲和力系统在复合培养基中生长的细胞中主要受到抑制。
Previous reports are in conflict as to the number of transport systems for glycine betaine inStaphylococcus aureus.Cells grown in complex medium exhibited a single transport system of moderate affinity. Cells grown in defined medium in the absence of glycine betaine showed a high affinity and a low affinity transport system. Cells grown in the presence of glycine betaine in the presence of osmotic stress in either complex or defined media accumulated large pools of internal glycine betaine. Smaller, but still significant, amounts of glycine betaine were accumulated by cells grown in its presence in either complex or defined media in the absence of osmotic stress. Cells grown in defined medium in the presence of glycine betaine in the presence or absence of osmotic stress showed lower rates of glycine betaine transport than cells grown in its absence. This suggests that glycine betaine transport is subject to feedback ortransinhibition by internal glycine betaine. This can explain the difference in observed kinetics in cells grown in complex or defined media, the high affinity system being predominantly inhibited in cells grown in complex medium.