4ZRL

Structure of the non canonical Poly(A) polymerase complex GLD-2 - GLD-3

Summary for 4ZRL

• Entry DOI: 10.2210/pdb4zrl/pdb
• Descriptor: Poly(A) RNA polymerase gld-2, Defective in germ line development protein 3, CHLORIDE ION, ... (4 entities in total)
• Functional Keywords: cytoplasmic poly(a)polymerase, post-transcriptional regulation, polyadenylation, non canonical poly(a) polymerase, transferase
• Biological source: Caenorhabditis elegans; More
• Cellular location: Cytoplasm : O17087 Q95ZK7
• Total number of polymer chains: 2
• Total formula weight: 50995.86

Authors

Nakel, K.,Bonneau, F.,Eckmann, C.R.,Conti, E. (deposition date: 2015-05-12, release date: 2015-07-08, Last modification date: 2024-11-20)

Primary citation

Nakel, K.,Bonneau, F.,Eckmann, C.R.,Conti, E.
Structural basis for the activation of the C. elegans noncanonical cytoplasmic poly(A)-polymerase GLD-2 by GLD-3.
Proc.Natl.Acad.Sci.USA, 112:8614-8619, 2015

PubMed Abstract: The Caenorhabditis elegans germ-line development defective (GLD)-2-GLD-3 complex up-regulates the expression of genes required for meiotic progression. GLD-2-GLD-3 acts by extending the short poly(A) tail of germ-line-specific mRNAs, switching them from a dormant state into a translationally active state. GLD-2 is a cytoplasmic noncanonical poly(A) polymerase that lacks the RNA-binding domain typical of the canonical nuclear poly(A)-polymerase Pap1. The activity of C. elegans GLD-2 in vivo and in vitro depends on its association with the multi-K homology (KH) domain-containing protein, GLD-3, a homolog of Bicaudal-C. We have identified a minimal polyadenylation complex that includes the conserved nucleotidyl-transferase core of GLD-2 and the N-terminal domain of GLD-3, and determined its structure at 2.3-Å resolution. The structure shows that the N-terminal domain of GLD-3 does not fold into the predicted KH domain but wraps around the catalytic domain of GLD-2. The picture that emerges from the structural and biochemical data are that GLD-3 activates GLD-2 both indirectly by stabilizing the enzyme and directly by contributing positively charged residues near the RNA-binding cleft. The RNA-binding cleft of GLD-2 has distinct structural features compared with the poly(A)-polymerases Pap1 and Trf4. Consistently, GLD-2 has distinct biochemical properties: It displays unusual specificity in vitro for single-stranded RNAs with at least one adenosine at the 3' end. GLD-2 thus appears to have evolved specialized nucleotidyl-transferase properties that match the 3' end features of dormant cytoplasmic mRNAs.

PubMed: 26124149
DOI: 10.1073/pnas.1504648112

Experimental method

X-RAY DIFFRACTION (2.28 Å)