Publications [#229108] of John M. Mercer

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Papers Published

  1. Siegel, SJ; Percopo, CM; Dyer, KD; Zhao, W; Roth, VL; Mercer, JM; Rosenberg, HF, RNase 1 genes from the family Sciuridae define a novel rodent ribonuclease cluster., Mammalian genome : official journal of the International Mammalian Genome Society, vol. 20 no. 11-12 (November, 2009), pp. 749-757 [doi] .
    (last updated on 2024/04/19)

    Abstract:
    The RNase A ribonucleases are a complex group of functionally diverse secretory proteins with conserved enzymatic activity. We have identified novel RNase 1 genes from four species of squirrel (order Rodentia, family Sciuridae). Squirrel RNase 1 genes encode typical RNase A ribonucleases, each with eight cysteines, a conserved CKXXNTF signature motif, and a canonical His(12)-Lys(41)-His(119) catalytic triad. Two alleles encode Callosciurus prevostii RNase 1, which include a Ser(18)<-->Pro, analogous to the sequence polymorphisms found among the RNase 1 duplications in the genome of Rattus exulans. Interestingly, although the squirrel RNase 1 genes are closely related to one another (77-95% amino acid sequence identity), the cluster as a whole is distinct and divergent from the clusters including RNase 1 genes from other rodent species. We examined the specific sites at which Sciuridae RNase 1s diverge from Muridae/Cricetidae RNase 1s and determined that the divergent sites are located on the external surface, with complete sparing of the catalytic crevice. The full significance of these findings awaits a more complete understanding of biological role of mammalian RNase 1s.