Topography of the surface of the Escherichia coli phosphotransferase system protein enzyme IIAglc that interacts with lactose permease.
Topography of the surface of the Escherichia coli phosphotransferase system protein enzyme IIAglc that interacts with lactose permease.
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与乳糖通透酶相互作用的大肠杆菌磷酸转移酶系统蛋白 IIAglc 的表面形貌。
DOI：
10.1021/bi9919596
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发表时间：
2000
期刊：
影响因子：
2.9
通讯作者：
Peterkofsky,A
中科院分区：
文献类型：
--
作者：
Sondej,M;Seok,YJ;Badawi,P;Koo,BM;Nam,TW;Peterkofsky,A
大肠杆菌磷酸烯醇丙酮酸：糖磷酸转移酶系统的酶IIAglc的非磷酸化形式抑制乳糖渗透酶催化的转运。我们（Seok等人（1997）Proc.Natl. Acad. Sci. U.S.A.94，13515 - 13519）先前使用放射性酶IIAglc表征了与酶IIAglc相互作用的乳糖通透酶的细胞质面上的区域。随后的研究（Sondej等人（1999）Proc.Natl. Acad. Sci. U.S.A.96，3525 - 3530）提出了与酶IIAglc相互作用的蛋白质上的共有结合序列。本研究的特点是一个区域的表面上的酶IIAglc接口与乳糖通透酶。乙酰化的赖氨酸残基的磺基琥珀酰亚胺乙酸酯处理酶IIAglc，但不是乳糖通透酶，降低了两种蛋白质之间的相互作用的程度。为了定位参与调节相互作用的酶IIAglc上的赖氨酸残基，对选定的赖氨酸残基进行诱变。将9个独立的赖氨酸转化为谷氨酸产生的蛋白质仍然能够从HPr接受磷酰基。除Lys 69外，所有修饰的蛋白质与野生型酶IIAglcin结合乳糖通透酶的测试一样有效。Lys 69突变体也有缺陷的磷酸转移到葡萄糖通透酶。为了获得关于接触表面的更多信息，对Lys 69附近的其他选定残基进行诱变处理，并检测其与乳糖通透酶的结合。在这些研究的基础上，提出了与乳糖通透酶相互作用的酶IIAglc的表面区域的模型。
The unphosphorylated form of enzyme IIAglcof theEscherichia coliphosphoenolpyruvate:sugar phosphotransferase system inhibits transport catalyzed by lactose permease. We (Seok et al. (1997)Proc. Natl. Acad. Sci. U.S.A.94, 13515−13519) previously characterized the area on the cytoplasmic face of lactose permease that interacts with enzyme IIAglc, using radioactive enzyme IIAglc. Subsequent studies (Sondej et al. (1999)Proc. Natl. Acad. Sci. U.S.A.96, 3525−3530) suggested consensus binding sequences on proteins that interact with enzyme IIAglc. The present study characterizes a region on the surface of enzyme IIAglcthat interfaces with lactose permease. Acetylation of lysine residues by sulfosuccinimidyl acetate treatment of enzyme IIAglc, but not lactose permease, reduced the degree of interaction between the two proteins. To localize the lysine residue(s) on enzyme IIAglcthat is(are) involved in the regulatory interaction, selected lysine residues were mutagenized. Conversion of nine separate lysines to glutamic acid resulted in proteins that were still capable of phosphoryl acceptance from HPr. Except for Lys69, all the modified proteins were as effective as the wild-type enzyme IIAglcin a test for binding to lactose permease. The Lys69 mutant was also defective in phosphoryl transfer to glucose permease. To derive further information concerning the contact surface, additional selected residues in the vicinity of Lys69 were mutagenized and tested for binding to lactose permease. On the basis of these studies, a model for the region of the surface of enzyme IIAglcthat interacts with lactose permease is proposed.