Identification of a novel member of 2H phosphoesterases, 2',5'-oligoadenylate degrading ribonuclease from the oyster Crassostrea gigas.

Identification of a novel member of 2H phosphoesterases, 2',5'-oligoadenylate degrading ribonuclease from the oyster Crassostrea gigas. Biochimie. 2018 Sep 05;: Authors: Lopp A, Reintamm T, Kuusksalu A, Olspert A, Kelve M Abstract Several genes of IFN-mediated pathways in vertebrates, among them the genes that participate in the 2',5'-oligoadenylate synthetase (OAS)/RNase L pathway, have been identified in C. gigas. In the present study, we identified genes, which encode proteins having 2',5'-oligoadenylate degrading activity in C. gigas. These proteins belong to the 2H phosphoesterase superfamily and have sequence similarity to the mammalian A kinase anchoring protein 7 (AKAP7) central domain, which is responsible for the 2',5'-phosphodiesterase (2',5'-PDE) activity. Comparison of the genomic structures of C. gigas proteins with that of AKAP7 suggests that these enzymes originate from a direct common ancestor. However, the identified nucleases are not typical 2',5'-PDEs. The found enzymes catalyse the degradation of 2',5'-linked oligoadenylates in a metal-ion-independent way, yielding products with 2',3' -cyclic phosphate and 5'-OH termini similarly to the 3'-5' bond cleavage in RNA, catalyzed by metal-independent ribonucleases. 3',5'-linked oligoadenylates are not substrates for them. The preferred substrates for the C. gigas enzymes are 5'-triphosphorylated 2',5'-oligoadenylates, whose major cleavage reaction results in the remova...
Source: Biochimie - Category: Biochemistry Authors: Tags: Biochimie Source Type: research