GENOMIC ORGANIZATION OF THE HUMAN GENE (CA5) AND PSEUDOGENE FOR MITOCHONDRIAL CARBONIC-ANHYDRASE-V AND THEIR LOCALIZATION TO CHROMOSOME-16QAND CHROMOSOME-16P

Carbonic anhydrase V (CA V) is expressed in mitochondrial matrix in li ver and several other tissues. It is of interest for its putative role s in providing bicarbonate to carbamoyl phosphate synthetase for ureag enesis and to pyruvate carboxylase for gluconeogenesis and its possibl e importance in explaining certain inherited metabolic disorders with hyperammonemia and hypoglycemia. Following the recent characterization of the cDNA for human CA V, we report the isolation of the human gene from two lambda genomic libraries and its characterization. The CA V gene (CA5) is approximately 50 kb long and contains 7 exons and 6 intr ons. The exon-intron boundaries are found in positions identical to th ose determined for the previously described CA II, CA III, and CA VII genes. Libe the CA VII gene, CA5 does not contain typical TATA and CAA T promoter elements in the 5' flanking region but does contain a TTTAA sequence 147 nucleotides upstream of the initiation codon. CA5 also c ontains a 12-bp CT-rich segment beginning 13 bp downstream of the poly adenylation signal in the 3' untranslated region of exon 7. FISH analy sis allowed CA5 to be assigned to chromosome 16q24.3. An unprocessed p seudogene containing sequence homologous to exons 3-7 and introns 3-6 was also isolated and was assigned by FISH analysis to chromosome 16p1 1.2-p12. (C) 1995 Academic Press, Inc.