Department of Pharmacy, University of Patras, Patras, Greece.
Biomol NMR Assign. 2022 Oct;16(2):379-384. doi: 10.1007/s12104-022-10107-1. Epub 2022 Sep 6.
Soluble guanylate cyclase (sGC) is considered as the primary NO receptor across several known eukaryotes. The main interest regarding the biological role and its function, focuses on the H-NOX domain of the β1 subunit. This domain in its active form bears a ferrous b type heme as prosthetic group, which facilitates the binding of NO and other diatomic gases. The key point that still needs to be answered is how the protein selectively binds the NO and how the redox state of heme and coordination determines H-NOX active state upon binding of diatomic gases. H-NOX domain is present in the genomes of both prokaryotes and eukaryotes, either as a stand-alone protein domain or as a partner of a larger polypeptide. The biological functions of these signaling modules for a wide range of genomes, diverge considerably along with their ligand binding properties. In this direction, we examine the prokaryotic H-NOX protein domain from Nostoc punctiforme (Npun H-NOX). Herein, we first report the almost complete NMR backbone and side-chain resonance assignment (H, C, N) of Npun H-NOX domain together with the NMR chemical shift-based prediction of the domain's secondary structure elements.
可溶性鸟苷酸环化酶（sGC）被认为是几种已知真核生物中主要的 NO 受体。关于其生物学作用和功能的主要关注点集中在β1 亚基的 H-NOX 结构域。该结构域在其活性形式下带有亚铁 b 型血红素作为辅基，这有利于 NO 和其他双原子气体的结合。仍需要回答的关键问题是蛋白质如何选择性地结合 NO，以及血红素的氧化还原状态和配位如何在结合双原子气体时决定 H-NOX 的活性状态。H-NOX 结构域存在于原核生物和真核生物的基因组中，要么作为独立的蛋白质结构域，要么作为更大多肽的伴侣。这些信号模块在广泛的基因组中的生物学功能因其配体结合特性而有很大差异。在这方面，我们研究了来自念珠藻（Nostoc punctiforme）的原核 H-NOX 蛋白结构域（Npun H-NOX）。在这里，我们首次报道了 Npun H-NOX 结构域的几乎完整的 NMR 骨架和侧链共振分配（H、C、N），以及基于 NMR 化学位移的结构域二级结构元件的预测。
