Characterization of the P1B-5ATPase Hemerythrin-like and Metal-Binding Domains

描述(申请人提供)：维持金属动态平衡对正常代谢功能至关重要，体内金属流入/流出必须严格控制。控制金属转运的一种方式是通过P1B型ATPase，这是一个完整的膜蛋白超家族，将ATP水解酶与跨膜过渡金属阳离子转运连接起来。关于P1B-5-ATPase有很多未知之处，包括金属底物(S)的特性以及该酶的C末端杂氯菊酯(HR)样结构域的功能。这项建议旨在利用光谱和结构技术，通过探索C-末端双铁中心与生理相关气体O2和NO的相互作用来阐明HR样结构域的功能。此外，这个建议试图建立天然金属底物(S)的身份，它结合在P1B-5-ATPase的跨膜区。将进行光谱和结构工作，以探索金属底物(S)与P1B-5 ATPase多肽之间相互作用的性质。这些研究将有助于阐明P1B-5-ATPase家族中HR样结构域的功能。此外，这项工作将促进对P1B-5-ATPase在过渡金属运输中的功能的理解。

DESCRIPTION (provided by applicant): Maintaining metal homeostasis is essential for normal metabolic functions, and metal influx/egress must be tightly managed in vivo. One manner in which metal transport is controlled is via the P1B-type ATPases, which are a superfamily of integral membrane proteins that couple ATP-hydrolysis to transmembrane transition metal cation transport. Much is unknown about the P1B-5-ATPase, including the identity of the metal substrate(s) and the function of the enzyme's C-terminal hemerythrin(Hr)-like domain. This proposal aims to use spectroscopic and structural techniques to elucidate the function of the Hr-like domain by exploring the interaction of the C- terminal diiron center with the physiologically relevant gases O2 and NO. Furthermore, this proposal seeks to establish the identity of the native metal substrate(s) that binds in the transmembrane region of the P1B-5- ATPase. Spectroscopic and structural work will be undertaken in order to probe the nature of interaction between the metal substrate(s) and the P1B-5 ATPase polypeptide. These studies will help elucidate the function of the Hr-like domain in the P1B-5-ATPase family. Moreover, this work will advance the understanding of the function of the P1B-5-ATPase in transition metal transport.