Mapping of steroid 21-hydroxylase genes adjacent to complement component C4 genes in HLA, the major histocompatibility complex in man

Proc Natl Acad Sci U S A. 1985 Jan;82(2):521-5. doi: 10.1073/pnas.82.2.521.


The genes for four components (C) of complement in the human major histocompatibility complex (HLA) have been aligned previously in a series of overlapping cosmid cloned inserts. Those inserts, which contained the two C4 genes C4A and C4B, hybridized with human adrenal mRNA, indicating that they contain a gene expressed in the adrenal. The mRNA fraction of 2.4 kilobases (kb) hybridizes with genomic DNA of 4.5 kb, which is duplicated and lies about 1.5 kb 3' of both the C4A and the C4B complement genes. Sequencing of a 430-base section and comparison with the published cDNA sequence of bovine cytochrome P-450 21-hydroxylase, peptide sequences of porcine 21-hydroxylase, and a cDNA sequence of a rat liver cytochrome P-450 identified the gene as coding for human steroid 21-hydroxylase [steroid,hydrogen-donor:oxygen oxidoreductase (21-hydroxylating), EC]. Mapping of the gene was helped by use of a synthetic oligonucleotide based on the bovine cDNA sequence.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adrenal Glands / analysis
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cattle
  • Cloning, Molecular
  • Complement C4 / genetics*
  • Complement C4a
  • Complement C4b
  • DNA / analysis
  • Humans
  • Major Histocompatibility Complex*
  • Nucleic Acid Hybridization
  • RNA, Messenger / analysis
  • Rats
  • Steroid 21-Hydroxylase / genetics*
  • Steroid Hydroxylases / genetics*
  • Swine


  • Complement C4
  • RNA, Messenger
  • Complement C4a
  • Complement C4b
  • DNA
  • Steroid Hydroxylases
  • Steroid 21-Hydroxylase

Associated data

  • GENBANK/K02771