128kDa http://identifiers.org/mgd/MGI:108014 D630020H17Rik Polr1b Rpo1-2|RPA2|128kDa|D630020H17Rik|RPA116 genetic mapping RPA116 Rpo1-2 + O Gene MGI:108014 protein coding gene RPA2 polymerase (RNA) I polypeptide B