PRIMARY STRUCTURE OF MAJOR OUTER-MEMBRANE PROTEIN-II-STAR (OMPA PROTEIN) OF ESCHERICHIA-COLI K-12
PRIMARY STRUCTURE OF MAJOR OUTER-MEMBRANE PROTEIN-II-STAR (OMPA PROTEIN) OF ESCHERICHIA-COLI K-12
复制标题
DOI：
10.1073/pnas.77.8.4592
复制
发表时间：
1980-01-01
期刊：
影响因子：
--
通讯作者：
HENNING, U
中科院分区：
文献类型：
--
作者：
CHEN, R;SCHMIDMAYR, W;HENNING, U
对大肠杆菌主要外膜蛋白Ⅱ *（ompA蛋白）的氨基酸序列进行了分析。coliK-12进行测定。跨膜多肽由325个残基组成，导致MW为35，159。蛋白质的跨膜部分位于残基1和177之间。在蛋白质的这一部分中，存在主要为亲脂性的27-残基片段，其可能以主要为α-氨基的方式跨越膜。螺旋构象，或者该片段的19个残基的延伸可以线性地穿过膜。在外膜内部存在序列-Ala-Pro-Ala-Pro-Ala-Pro-Ala-Pro-，其类似于免疫球蛋白铰链区中的-Cys-Pro-Pro-Cys-Pro-序列，可以呈现聚脯氨酸螺旋的构象。计算机分析没有揭示一个明确的整体模式的内部同源性的蛋白质，除了-丙氨酸-Pro-重复，只有1个局部区域（2个相邻的dodecapeptide段）显示出一定的重复性。同样的分析没有产生内部同源性的证据，在以前确定的序列的外膜蛋白I（孔蛋白），也没有任何明显的相似性之间检测到跨膜蛋白I和II*。
The amino acid sequence of major outer membrane protein II* (ompA protein) from E. coli K-12 was determined. The transmembrane polypeptide consists of 325 residues, resulting in a MW of 35,159. The transmembrane part of the protein is located between residues 1 and 177. In this part of the protein a predominantly lipophilic 27-residue segment exists that perhaps spans the membrane in a mostly .alpha.-helical conformation, or a 19-residue stretch of this segment might traverse the membrane linearly. Inside the outer membrane a sequence -Ala-Pro-Ala-Pro-Ala-Pro-Ala-Pro- exists that, analogous to the -Cys-Pro-Pro-Cys-Pro- sequence in the hinge region of immunoglobulin, could assume the conformation of a polyproline helix. Computer analysis did not reveal a clear overall pattern of internal homology in the protein; besides the -Ala-Pro- repeat, only 1 local area (2 adjacent dodecapeptide segments) shows some repetitiveness. The same analysis did not produce evidence for internal homology in the previously determined sequence of outer membrane protein I (porin) nor was any marked resemblance detected between transmembrane proteins I and II*.