RbfA (ribosome binding factor A; 15.2 kDa) is a protein involved in ribosome biogenesis and has been shown to be important for growth at low temperatures and to act as a suppressor for a cold-sensitive mutation (C23U) in the ribosomal RNA of the small 30S ribosomal subunit. The 3D structure of isolated RbfA has been determined from several organisms showing that RbfA has type-II KH-domain fold topology similar to the KH domain of another assembly factor, Era, whose overexpression can compensate for the deletion of rbfA, suppressing both the cold sensitivity and abnormal accumulation of 17S rRNA in rbfA knockout stains. Interestingly, a RbfAΔ25 variant used in previous NMR studies, truncated at the C-terminal domain to remove 25 unstructured residues causing aggregation at room temperature, was biologically active in the sense that it could complement a knock-out of wildtype RbfA, although it did not act as a suppressor for a 16S cold-sensitive mutation (C23U), nor did it interact stably with the 30S subunit. To complement this work, we report the ¹H, ¹³C, and ¹⁵ N backbone and sidechain NMR resonance assignments of full length RbfA from Escherichia coli measured under physiological conditions (pH 7.6). This construct contains seven additional C-terminal residues from the cloning (i.e. one alanine and six residues from the HRV 3C cleavage site) and no aggregation issues were observed over a 1-week period at 293 K. The assignment data has been deposited in the BMRB data bank under Accession No. 27857.

中文翻译：

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来自大肠杆菌的核糖体成熟因子 RbfA 的主链和侧链 NMR 分配。

RbfA（ř ibosome b inding ˚F演员A; 15.2 kDa) 是一种参与核糖体生物合成的蛋白质，已被证明对低温下的生长很重要，并作为 30S 核糖体小亚基核糖体 RNA 冷敏感突变 (C23U) 的抑制因子。从几种生物体中确定了分离的 RbfA 的 3D 结构，表明 RbfA 具有类似于另一个组装因子 Era 的 KH 域的 II 型 KH 域折叠拓扑结构，其过表达可以补偿 rbfA 的缺失，抑制冷rbfA 敲除染色中 17S rRNA 的敏感性和异常积累。有趣的是，之前 NMR 研究中使用的 RbfAΔ25 变体在 C 端结构域被截断以去除 25 个导致室温下聚集的非结构化残基，从某种意义上说，它具有生物活性，因为它可以补充敲除野生型 RbfA，尽管它不作为 16S 冷敏感突变 (C23U) 的抑制因子，也不与 30S 亚基稳定相互作用。为了补充这项工作，我们报告了在生理条件 (pH 7.6) 下测量的 来自大肠杆菌的全长 RbfA 的¹ H、¹³ C 和¹⁵ N 主链和侧链 NMR 共振分配。该构建体包含来自克隆的七个额外的 C 端残基（即一个丙氨酸和六个来自 HRV 3C 切割位点的残基），并且在 293 K 下的 1 周内未观察到聚集问题。分配数据已存放在入藏号为 27857 的 BMRB 数据库。