A protein binding to the J kappa recombination sequence of immunoglobulin genes contains a sequence related to the integrase motif.
Site-specific recombination requires conserved DNA sequences specific to each system, and system-specific proteins that recognize specific DNA sequences. The site-specific recombinases seem to fall into at least two families, based on their protein structure and chemistry of strand breakage. One of these is the resolvase-invertase family, members of which seem to form a serine-phosphate linkage with DNA. Members of the other family, called the integrase family, contain a conserved tyrosine residue that forms a covalent linkage with the 3'-phosphate of DNA at the site of recombination. Structural comparison of integrases shows that these proteins share a highly conserved 40-residue motif. V-(D)-J recombination of the immunoglobulin gene requires conserved recombination signal sequences (RS) of a heptamer CACTGTG and a T-rich nonamer GGTTTTTGT, which are separated by a spacer sequence of either 12 or 23 bases We have recently purified, almost to homogeneity, a protein that specifically binds to the immunoglobulin J kappa RS containing the 23-base-pair spacer sequence. By synthesizing probes on the basis of partial amino-acid sequences of the purified protein, we have now isolated and characterized the complementary DNA of this protein. The amino-acid sequence deduced from the cDNA sequence reveals that the J kappa RS-binding protein has a sequence similar to the 40-residue motif of integrases of phages, bacteria and yeast, indicating that this protein could be involved in V-(D)-J recombination as a recombinase.
Matsunami
N
N
Department of Medical Chemistry, Kyoto University Faculty of Medicine, Japan.
Hamaguchi
Y
Y
Yamamoto
Y
Y
Kuze
K
K
Kangawa
K
K
Matsuo
H
H
Kawaichi
M
M
Honjo
T
T
D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D001483:Base Sequence; D002460:Cell Line; D004254:DNA Nucleotidyltransferases / Q000235:genetics*; D004251:DNA Transposable Elements; D004268:DNA-Binding Proteins / Q000235:genetics / Q000302:isolation & purification; D015321:Gene Rearrangement; D005803:Genes, Immunoglobulin; D007145:Immunoglobulin kappa-Chains / Q000235:genetics*; D019426:Integrases; D051379:Mice; D008969:Molecular Sequence Data; D010957:Plasmids; D011995:Recombination, Genetic; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D004251:DNA Transposable Elements; D004268:DNA-Binding Proteins; D007145:Immunoglobulin kappa-Chains; D004254:DNA Nucleotidyltransferases; D019426:Integrases