当前位置: X-MOL 学术Acta Cryst. D › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
The β-link motif in protein architecture
Acta Crystallographica Section D ( IF 2.6 ) Pub Date : 2021-08-04 , DOI: 10.1107/s2059798321006768
David P Leader 1 , E James Milner-White 1
Affiliation  

The β-link is a composite protein motif consisting of a G1β β-bulge and a type II β-turn, and is generally found at the end of two adjacent strands of antiparallel β-sheet. The 1,2-positions of the β-bulge are also the 3,4-positions of the β-turn, with the result that the N-terminal portion of the polypeptide chain is orientated at right angles to the β-sheet. Here, it is reported that the β-link is frequently found in certain protein folds of the SCOPe structural classification at specific locations where it connects a β-sheet to another area of a protein. It is found at locations where it connects one β-sheet to another in the β-sandwich and related structures, and in small (four-, five- or six-stranded) β-barrels, where it connects two β-strands through the polypeptide chain that crosses an open end of the barrel. It is not found in larger (eight-stranded or more) β-barrels that are straightforward β-meanders. In some cases it initiates a connection between a single β-sheet and an α-helix. The β-link also provides a framework for catalysis in serine proteases, where the catalytic serine is part of a conserved β-link, and in cysteine proteases, including Mpro of human SARS-CoV-2, in which two residues of the active site are located in a conserved β-link.

中文翻译:

蛋白质结构中的 β-link 基序

β-link 是由 G1β β-bulge 和 II 型 β-turn 组成的复合蛋白质基序,通常位于反平行 β-折叠的两条相邻链的末端。β-凸起的 1,2-位也是 β-转角的 3,4-位,结果是多肽链的 N-末端部分与 β-折叠成直角。在这里,据报道,β-link 经常在 SCOPe 结构分类的某些蛋白质折叠中发现,在特定位置,它将β-折叠连接到蛋白质的另一个区域。它存在于 β-夹层和相关结构中将一个 β-折叠连接到另一个β-折叠的位置,以及在小的(四、五或六链)β-桶中,它通过穿过桶开口端的多肽链。在较大的(八股或更多)β-桶中没有发现它是直接的β-曲折。在某些情况下,它会启动单个 β-折叠和 α-螺旋之间的连接。β-link 还为丝氨酸蛋白酶(其中催化丝氨酸是保守 β-link 的一部分)和半胱氨酸蛋白酶(包括 M人类 SARS-CoV-2 的pro,其中活性位点的两个残基位于保守的 β-link 中。
更新日期:2021-08-04
down
wechat
bug