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Publication Abstract from PubMed

Cellular RNA-protein (RNP) granules are ubiquitous and have fundamental roles in biology and RNA metabolism, but the molecular basis of their structure, assembly, and function is poorly understood. Using nematode "P-granules" as a paradigm, we focus on the PGL granule scaffold protein to gain molecular insights into RNP granule structure and assembly. We first identify a PGL dimerization domain (DD) and determine its crystal structure. PGL-1 DD has a novel 13 alpha-helix fold that creates a positively charged channel as a homodimer. We investigate its capacity to bind RNA and discover unexpectedly that PGL-1 DD is a guanosine-specific, single-stranded endonuclease. Discovery of the PGL homodimer, together with previous results, suggests a model in which the PGL DD dimer forms a fundamental building block for P-granule assembly. Discovery of the PGL RNase activity expands the role of RNP granule assembly proteins to include enzymatic activity in addition to their job as structural scaffolds.

PGL germ granule assembly protein is a base-specific, single-stranded RNase.,Aoki ST, Kershner AM, Bingman CA, Wickens M, Kimble J Proc Natl Acad Sci U S A. 2016 Jan 19. pii: 201524400. PMID:26787882^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.