Urabe Hiroaki, Aoyagi Narumi, Ogawara Hiroshi, Motojima Kiyoto
Department of Biochemistry, Meiji Pharmaceutical University, Kiyose, Tokyo 204-8588, Japan.
Biosci Biotechnol Biochem. 2008 Mar;72(3):778-85. doi: 10.1271/bbb.70658. Epub 2008 Mar 7.
We identified and characterized the gene encoding a new eukaryotic-type protein kinase from Streptomyces coelicolor A3(2) M145. PkaD, consisting of 598 amino acid residues, contained the catalytic domain of eukaryotic protein kinases in the N-terminal region. A hydrophobicity plot indicated the presence of a putative transmembrane spanning sequence downstream of the catalytic domain, suggesting that PkaD is a transmembrane protein kinase. The recombinant PkaD was found to be phosphorylated at the threonine and tyrosine residues. In S. coelicolor A3(2), pkaD was transcribed as a monocistronic mRNA, and it was expressed constitutively throughout the life cycle. Disruption of chromosomal pkaD resulted in a significant loss of actinorhodin production. This result implies the involvement of pkaD in the regulation of secondary metabolism.
我们从天蓝色链霉菌A3(2) M145中鉴定并表征了一个编码新型真核型蛋白激酶的基因。PkaD由598个氨基酸残基组成，在N端区域含有真核蛋白激酶的催化结构域。疏水性分析表明，在催化结构域下游存在一个推定的跨膜序列，这表明PkaD是一种跨膜蛋白激酶。发现重组PkaD在苏氨酸和酪氨酸残基处发生磷酸化。在天蓝色链霉菌A3(2)中，pkaD转录为单顺反子mRNA，并在整个生命周期中组成型表达。染色体pkaD的破坏导致放线紫红素产量显著损失。这一结果表明pkaD参与了次级代谢的调控。
