CHARACTERIZATION OF THE HUMAN SDHC GENE ENCODING ONE OF THE INTEGRAL MEMBRANE-PROTEINS OF SUCCINATE-QUINONE OXIDOREDUCTASE IN MITOCHONDRIA

Complex II of mitochondria contains succinate dehydrogenase and subuni ts to link this enzyme directly to the inner mitochondrial membrane. T he four peptides of this complex are the flavoprotein (Fp) and iron-su lfur protein (Ip) of the dehydrogenase, and two integral membrane prot eins referred to as C-II.3 and C-II.4. Their respective genes in mamma ls are SDHA, SDHB, SDHC and SDHD,(2) in order of decreasing molecular weights of the peptides. In this paper we describe the identification of two pseudogenes and;the complete characterization and mapping of th e active SDHC gene in humans. The active gene, encoding a small peptid e of 15.5 kDa, has six exons and five introns extending over 35 kb. It has been mapped at position 1q21, adjacent to the pericentric heteroc hromatin on the long arm of chromosome 1. Approximately 1 kb of the pr omoter region has also been sequenced and examined for sequence motifs suggesting the binding of known transcription factors. Several potent ial sites for the nuclear respiratory factors NRF-1 and NRF-2 were ide ntified. (C) 1998 Elsevier Science B.V. All rights reserved.