Identification of a new human CYP2A gene fragment with close linkage to CYP2GP1.
Human genomic libraries were screened to identify CYP2G-related cytochrome P450 genes. A genomic fragment comprising exons 7 through 9 of CYP2GP1 and exons 6 through 9 of a previously unidentified CYP2A gene, designated CYP2A7P2, was isolated from an EMBL3 library; the two genes were arranged in outward opposite directions with about 8 kbp of intervening sequence. The same structure was also detected in a bacteriophage P1 clone, which contained a full-length CYP2GP1 gene, exons 6 through 9 of CYP2A7P2, and the CYP2B7 gene. However, additional CYP2A-related exons as well as other CYP2A genes, CYP2A7P1, CYP2B6, CYP2F1, and CYP2GP2 were not detected. These results indicate that CYP2A7P2 is located near CYP2B7 in the middle of the CYP2A-2B-2F gene cluster on chromosome 19. Furthermore, an analysis of CYP2A sequence alignment suggests that CYP2A7P2 may be derived from the same ancestral gene that gave rise to CYP2A7P1, which was corrupted by a large insertion at intron 5.
Sheng
J
J
Wadsworth Center, New York State Department of Health, State University of New York at Albany Albany, NY 12201-0509, USA.
Hua
Z
Z
Guo
J
J
Caggana
M
M
Ding
X
X
D000328:Adult; D000595:Amino Acid Sequence; D001483:Base Sequence; D002888:Chromosomes, Human, Pair 19; D003577:Cytochrome P-450 Enzyme System / Q000737:chemistry / Q000235:genetics*; D004247:DNA; D005091:Exons; D005260:Female; D008040:Genetic Linkage; D006801:Humans; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D013250:Steroid Hydroxylases / Q000737:chemistry / Q000235:genetics*
D004247:DNA; D003577:Cytochrome P-450 Enzyme System; D013250:Steroid Hydroxylases; C022657:steroid hormone 6-beta-hydroxylase