6TZN

Structure of S. pombe telomerase accessory protein Pof8 C-terminal domain

Summary for 6TZN

• Entry DOI: 10.2210/pdb6tzn/pdb
• Descriptor: Protein pof8, NITRATE ION (3 entities in total)
• Functional Keywords: rrm, larp7, rna binding protein, lsm binding
• Biological source: Schizosaccharomyces pombe (strain 972 / ATCC 24843) (Fission yeast)
• Total number of polymer chains: 1
• Total formula weight: 14522.48

Authors

Basu, R.S.,Cascio, D.,Eichhorn, C.D.,Feigon, J. (deposition date: 2019-08-12, release date: 2020-08-19, Last modification date: 2024-03-13)

Primary citation

Basu, R.,Eichhorn, C.D.,Cheng, R.,Peterson, R.D.,Feigon, J.
Structure of S. pombe telomerase protein Pof8 C-terminal domain is an xRRM conserved among LARP7 proteins.
Rna Biol., 18:1181-1192, 2021

PubMed Abstract: La-related proteins 7 (LARP7) are a class of RNA chaperones that bind the 3' ends of RNA and are constitutively associated with their specific target RNAs. In metazoa, Larp7 binds to the long non-coding 7SK RNA as a core component of the 7SK RNP, a major regulator of eukaryotic transcription. In the ciliate the LARP7 protein p65 is a component of telomerase, an essential ribonucleoprotein complex that maintains the telomeric DNA at eukaryotic chromosome ends. p65 is important for the ordered assembly of telomerase RNA (TER) with telomerase reverse transcriptase. Unexpectedly, Pof8 was recently identified as a LARP7 protein and a core component of fission yeast telomerase essential for biogenesis. LARP7 proteins have a conserved N-terminal La motif and RRM1 (La module) and C-terminal RRM2 with specific RNA substrate recognition attributed to RRM2, first structurally characterized in p65 as an atypical RRM named xRRM. Here we present the X-ray crystal structure and NMR studies of Pof8 RRM2. Sequence and structure comparison of Pof8 RRM2 to p65 and human Larp7 xRRMs reveals conserved features for RNA binding with the main variability in the length of the non-canonical helix α3. This study shows that Pof8 has conserved xRRM features, providing insight into TER recognition and the defining characteristics of the xRRM.

PubMed: 33131423
DOI: 10.1080/15476286.2020.1836891

Experimental method

X-RAY DIFFRACTION (1.35 Å)