Structure of genes encoding chromosomal HMG1 proteins from maize

Abstract

The high mobility group (HMG) proteins of the HMG1 family are architectural proteins in chromatin that are considered to facilitate the formation of complex nucleoprotein structures in various biological processes such as transcription and recombination. Plants express a variety of these non-sequence-specific DNA-bending proteins. The sequences encoding the maize HMGa and HMGc1 proteins were isolated from a genomic DNA library. Determination of the nucleotide sequences of these genes revealed that the coding region of both genes has a similar genomic structure, comprising seven exons and six introns. The positioning of the introns is conserved between the two genes, whereas the number of introns and their positions are entirely different in the related animal genes. In the 5' flanking region of the hmgc1 gene, a copia-like retrotransposon was identified. In addition to the genes encoding HMGa and HMGc1, several genomic fragments (retropseudo gene, fragments of the genes) were isolated and characterised.