RRM domain of human RBM7: purification, crystallization and structure determination

• Published in: Acta crystallographica. Section F, Structural biology communications Vol. 72; no. 5; pp. 397 - 402
• Main Authors: Sofos, Nicholas, Winkler, Mikael B. L., Brodersen, Ditlev E.
• Format: Journal Article
• Language: English
• Published: 5 Abbey Square, Chester, Cheshire CH1 2HU, England International Union of Crystallography 01.05.2016
• Subjects: Assembly; Cloning, Molecular; Crystal structure; Crystallization; Crystallography, X-Ray; Decay; Human; Humans; Molecular structure; NEXT complex; Protein Conformation; Protein Domains; Proteins; Research Communications; Ribonucleic acids; RNA degradation; RNA-Binding Proteins - chemistry; RNA-Binding Proteins - genetics; RNA-Binding Proteins - isolation & purification; RRM domain; X-ray crystallography; Yeast; RRM domain; X-ray crystallography; RNA degradation; human; NEXT complex
• ISSN: 2053-230X; 2053-230X
• DOI: 10.1107/S2053230X16006129

RNA decay is an important process that is essential for controlling the abundance, quality and maturation of transcripts. In eukaryotes, RNA decay in the 3′–5′ direction is carried out by the exosome, an RNA‐degradation machine that is conserved from yeast to humans. A range of cofactors stimulate the enzymatic activity of the exosome and serve as adapters for the many RNA substrates. In human cells, the exosome associates with the heterotrimeric nuclear exosome targeting (NEXT) complex consisting of the DExH‐box helicase hMTR4, the zinc‐finger protein hZCCHC8 and the RRM‐type protein hRBM7. Here, the 2.5 Å resolution crystal structure of the RRM domain of human RBM7 is reported. Molecular replacement using a previously determined solution structure of RBM7 was unsuccessful. Instead, RBM8 and CBP20 RRM‐domain crystal structures were used to successfully determine the RBM7 structure by molecular replacement. The structure reveals a ring‐shaped pentameric assembly, which is most likely a consequence of crystal packing. The X‐ray crystal structure of the RRM domain of human RBM7 reveals a pentameric assembly.