Crystallographic study of a MATE transporter presents a difficult case in structure determination with low-resolution, anisotropic data and crystal twinning.

MATE 转运器的晶体学研究在低分辨率的结构确定中提出了困难的情况 ，各向异性数据和晶体孪生。

• 发表时间: Nov 2015
• 来源期刊: Acta Crystallogr D Biol Crystallogr
• DOI: 10.1107/S1399004715016995
• PMID: 26527145
• 文章类型: Journal Article
• 作者列表: Symersky J,Guo Y,Wang J,Lu M

关键词: MATE transporter; data anisotropy; difference Fourier analysis; multidrug resistance; twinning

Mesh: Anisotropy; Antiporters / chemistry metabolism; Bacterial Proteins / chemistry metabolism; Binding Sites; Crystallization; Crystallography, X-Ray; Fourier Analysis; Ligands; Models, Molecular; Neisseria gonorrhoeae / chemistry metabolism; Protein Conformation

Abstract

NorM from Neisseria gonorrhoeae (NorM-NG) belongs to the multidrug and toxic compound extrusion (MATE) family of membrane-transport proteins, which can extrude cytotoxic chemicals across cell membranes and confer multidrug resistance. Here, the structure determination of NorM-NG is described, which had been hampered by low resolution (∼ 4 Å), data anisotropy and pseudo-merohedral twinning. The crystal structure was solved using molecular replacement and was corroborated by conducting a difference Fourier analysis. The NorM-NG structure displays an extracellular-facing conformation, similar to that of NorM-NG bound to a crystallization chaperone. The approaches taken to determine the NorM-NG structure and the lessons learned from this study are discussed, which may be useful for analyzing X-ray diffraction data with similar shortcomings.

摘要

来自淋病奈瑟菌的NorM（NorM-NG）属于膜转运蛋白的多药和毒性化合物挤出（MATE）家族，它可以在细胞膜上挤出细胞毒性化学物质并赋予多药耐药性。这里,描述了NorM-NG的结构确定，这受到低分辨率(4)的阻碍，数据各向异性和伪摩罗面体孪生。使用分子置换解决了晶体结构，并通过进行差分傅立叶分析来证实。NorM-NG结构显示面向细胞外的构象，类似于与结晶伴侣结合的NorM-NG。讨论了确定NorM-NG结构的方法以及从本研究中吸取的教训，这对于分析具有类似缺点的X射线衍射数据可能是有用的。