Structural and functional analysis of SilP, a P1-type ATPase from the sil family involved in bacterial silver resistance.

银(Ag+)是一种重金属，通常用于烧伤病房的绷带衬里和面霜中的添加剂，以帮助防止感染，因为重金属对细菌细胞具有高度毒性。由于使用银作为预防性治疗，某些细菌株对银产生了抗药性。对耐药细菌的分析发现，存在一个含有9个编码蛋白质的质粒，这些蛋白质被标记为Silp蛋白。我目前的研究重点是其中一种蛋白质Silp，这是一种P1B型ATPase，它以ATP为代价将Ag+从细菌的细胞质输出到细胞膜的周质。SILP遵循后Albers催化循环，在该循环中，蛋白质在输出Ag+的过程中有四种主要构象状态。我的研究的主要目的是利用结晶学、低温电子显微镜和中子散射来获得SIp的整体结构。除了整体结构的目的是在催化循环的四个阶段中的每一个阶段获得结构之外，这将给出蛋白质中金属运动的指示以及它如何输出Ag+。虽然主要目的是确定Silp的结构，但另一个目的是进行功能分析，以观察ATP的使用和Ag+输出速率以及Silp的其他生物物理方面。

Silver (Ag+) is a heavy metal commonly used within burns wards as a lining in bandages and as an additive within creams to help prevent infections, owing to heavy metals being highly toxic to bacterial cells. Due to the use of silver as a preventative treatment, certain strains of bacteria have developed resistance to silver. Analysis of the resistant bacteria identified the presence of a plasmid containing nine genes encoding for proteins believed to be involved in silver exportation, they were labelled sil proteins.My current research focuses on one of these proteins, SilP, this is a P1B-type ATPase that exports Ag+ from the cytoplasm of the bacterial into the periplasm of the cell membrane at the expense of ATP. SilP follows the Post-Albers catalytic cycle, wherein there are four main conformational states of the protein during exportation of Ag+. The main aim of my research looks at obtaining an overall structure of SilP, using both crystallography, Cryo-EM and neutron scattering. In addition to the overall structure is the aim of getting a structure at each of the four stages of the catalytic cycle, this would give an indication of metal movement within the protein and how it exports Ag+. Although the main aim is the structural determination of SilP, the other aims are to carry out functional assays looking at ATP usage and rate of Ag+ exportation as well as other biophysical aspects of SilP.