Bray Beverley A, Sutcliffe Iain C, Harrington Dean J
Division of Biomedical Sciences, University of Bradford, West Yorkshire, BD7 1DP, UK.
Antonie Van Leeuwenhoek. 2009 Jan;95(1):101-9. doi: 10.1007/s10482-008-9291-6. Epub 2008 Nov 4.
Metal ion acquisition and homeostasis are essential for bacterial survival, growth and physiology. A family of metal ion, ABC-type import systems have been identified in Gram-positive bacteria, in which the solute-binding proteins are predicted to be membrane-anchored lipoproteins. The prediction that the MtsA protein of Streptococcus agalactiae A909 is a lipoprotein was confirmed. The expression of MtsA was co-ordinately regulated by the presence of both manganese and ferrous ions suggesting that MtsA may be involved in the uptake of both these ions. MtsA was shown to be expressed at levels of ferrous ions known to be present in amniotic fluid, a growth medium for S. agalactiae during neonatal infection.
金属离子的获取与稳态对于细菌的生存、生长及生理功能至关重要。在革兰氏阳性菌中已鉴定出一类金属离子ABC型导入系统，其中溶质结合蛋白被预测为膜锚定脂蛋白。无乳链球菌A909的MtsA蛋白是脂蛋白这一预测得到了证实。MtsA的表达受锰离子和亚铁离子共同存在的协同调控，这表明MtsA可能参与这两种离子的摄取。研究表明，在已知存在于羊水（新生儿感染期间无乳链球菌的生长培养基）中的亚铁离子水平下，MtsA会表达。
