期刊
BIOCHEMICAL JOURNAL
卷 473, 期 -, 页码 1523-1536出版社
PORTLAND PRESS LTD
DOI: 10.1042/BCJ20160245
关键词
kinetic characterization; molecular dynamics; protein crystallography; RNase A superfamily; RNase k6; sulfate anion
资金
- Ministerio de Economia y Competitividad - FEDER funds [BFU2012-38695, BES-2010-036238]
- Generalitat de Catalunya [2014-SGR-728]
- Universitat Autonoma de Barcelona [406-02-02/2013]
Human RNase 6 is a cationic secreted protein that belongs to the RNase A superfamily. Its expression is induced in neutrophils and monocytes upon bacterial infection, suggesting a role in host defence. We present here the crystal structure of RNase 6 obtained at 1.72 angstrom (1 angstrom = 0.1 nm) resolution, which is the first report for the protein 3D structure and thereby setting the basis for functional studies. The structure shows an overall kidney-shaped globular fold shared with the other known family members. Three sulfate anions bound to RNase 6 were found, interacting with residues at the main active site (His(15), His(122) and Gln(14)) and cationic surface-exposed residues (His(36), His(39), Arg(66) and His(67)). Kinetic characterization, together with prediction of protein-nucleotide complexes by molecular dynamics, was applied to analyse the RNase 6 substrate nitrogenous base and phosphate selectivity. Our results reveal that, although RNase 6 is a moderate catalyst in comparison with the pancreatic RNase type, its structure includes lineage-specific features that facilitate its activity towards polymeric nucleotide substrates. In particular, enzyme interactions at the substrate 5' end can provide an endonuclease-type cleavage pattern. Interestingly, the RNase 6 crystal structure revealed a novel secondary active site conformed by the His(36)-His(39) dyad that facilitates the polynucleotide substrate catalysis.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据