%0 Journal Article
%T A human RNA polymerase II subunit is encoded by a recently generated multigene family
%A Sylvie Grandemange
%A Sophie Schaller
%A Shigeru Yamano
%A Stanislas Du Manoir
%A George V Shpakovski
%A Marie-Genevi¨¨ve Mattei
%A Claude Kedinger
%A Marc Vigneron
%J BMC Molecular Biology
%D 2001
%I BioMed Central
%R 10.1186/1471-2199-2-14
%X While those characterized so far for the human (h) RPB are also unique, we show that hRPB subunit 11 (hRPB11) is encoded by a multigene family, mapping on chromosome 7 at loci p12, q11.23 and q22. We focused on two members of this family, hRPB11a and hRPB11b: the first encodes subunit hRPB11a, which represents the major RPB11 component of the mammalian RPB complex ; the second generates polypeptides hRPB11b¦Á and hRPB11b¦Â through differential splicing of its transcript and shares homologies with components of the hPMS2L multigene family related to genes involved in mismatch-repair functions (MMR). Both hRPB11a and b genes are transcribed in all human tissues tested. Using an inter-species complementation assay, we show that only hRPB11b¦Á is functional in yeast. In marked contrast, we found that the unique murine homolog of RPB11 gene maps on chromosome 5 (band G), and encodes a single polypeptide which is identical to subunit hRPB11a.The type hRPB11b gene appears to result from recent genomic recombination events in the evolution of primates, involving sequence elements related to the MMR apparatus.In eukaryotes, mRNAs are transcribed by RNA polymerase II (RPB). To date, most studies have focused on the yeast polymerases. Yeast RPB consists of 12 polypeptides ranging from 220 to 6 kDa [1-3]. Much less is known about the human (h) RPB, although the sequences encoding the subunits homologous to the yeast RPB have been determined. Complementation experiments have shown that many yeast subunits may be replaced in vivo by their human counterparts indicating a remarkable functional conservation through evolution [4-8]. This supports the view that the 3D structure of the yeast RPB [9,10] can most likely be extended to other eukaryotic nuclear RPB molecules.We have undertaken the characterisation of the human RPB subunits. All the subunit genes identified so far are unique: hRPB1 (Ac N¡ã X74870-74) [11], hRPB2 (Ac N¡ã AC068261), hRPB3 (Ac N¡ã AC004382), hRPB4 (Ac N¡ã U89387) [7]
%U http://www.biomedcentral.com/1471-2199/2/14