Function analysis of a bacterial tyrosine kinase, BtkB, in Myxococcus xanthus
Function analysis of a bacterial tyrosine kinase, BtkB, in Myxococcus xanthus
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黄色粘球菌中细菌酪氨酸激酶 BtkB 的功能分析
DOI：
10.1111/j.1574-6968.2012.02651.x
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
Y.
中科院分区：
文献类型：
--
作者：
Kimura;Y.;Kato;T.;and Mori;Y.
黄色粘球菌BtkB由N-末端周质结构域和C-末端胞质酪氨酸激酶结构域组成。在[γ-32 P]ATP和MgCl 2存在下，BtkB的C端胞浆区发生自磷酸化，并用抗磷酸酪氨酸抗体检测到自磷酸化的BtkB，表明BtkB是一种细菌酪氨酸激酶。BY激酶在胞外多糖（EPS）的产生、抗生素抗性、应激反应和DNA代谢中发挥重要作用，黄色粘球菌btkB基因主要在生长期和子实体发育早期表达。当在高温（37 °C）下在营养培养基中培养时，与野生型相比，btkB突变体显示出降低的最大细胞密度。在饥饿条件下，btkB突变体的子实体和孢子形成时间比野生型菌株晚24 h左右。btkB突变体在发育过程中过量产生黄色素。此外，与野生型菌株相比，btkB突变体显示出EPS产量的降低。这些结果提示BtkB可能在M中发挥多重作用。黄色细胞
Myxococcus xanthusBtkB is composed of an N-terminal periplasmic domain and a C-terminal cytoplasmic tyrosine kinase domain. The C-terminal cytoplasmic domain of BtkB was autophosphorylated in the presence of [γ-32P]ATP and MgCl2, and the autophosphorylated BtkB was detected with antiphosphotyrosine antibody, suggesting that BtkB is a bacterial tyrosine (BY) kinase. BY kinases have been demonstrated in the production of extracellular polysaccharide (EPS), antibiotic resistance, stress response, and DNA metabolism.Myxococcus xanthus btkBgene was expressed mainly in the growth phase and early stages of fruiting body development. When cultured in nutrient medium at high temperature (37 °C),btkBmutant showed reduced maximum cell density as compared to the wild type. Under starvation conditions,btkBmutant cells formed fruiting bodies and spores about 24 h later than the wild-type strain. ThebtkBmutant overproduced yellow pigment during development. Also,btkBmutant showed a decrease in EPS production when compared with the wild-type strain. These results suggested that BtkB may play multiple roles inM. xanthuscells.