An open reading frame in intron seven of the sea urchin DNA-methyltransferase gene codes for a functional AP1 endonuclease.
Analysis of the genome structure of the Paracentrotus lividus (sea urchin) DNA methyltransferase (DNA MTase) gene showed the presence of an open reading frame, named METEX, in intron 7 of the gene. METEX expression is developmentally regulated, showing no correlation with DNA MTase expression. In fact, DNA MTase transcripts are present at high concentrations in the early developmental stages, while METEX is expressed at late stages of development. Two METEX cDNA clones (Met1 and Met2) that are different in the 3' end have been isolated in a cDNA library screening. The putative translated protein from Met2 cDNA clone showed similarity with Escherichia coli endonuclease III on the basis of sequence and predictive three-dimensional structure. The protein, overexpressed in E. coli and purified, had functional properties similar to the endonuclease specific for apurinic/apyrimidinic (AP) sites on the basis of the lyase activity. Therefore the open reading frame, present in intron 7 of the P. lividus DNA MTase gene, codes for a functional AP endonuclease designated SuAP1.
Cioffi
Anna Valentina
AV
Biochemistry and Molecular Biology Laboratory, Stazione Zoologica A. Dohrn, Villa Comunale 80121 Naples, Italy.
Ferrara
Diana
D
Cubellis
Maria Vittoria
MV
Aniello
Francesco
F
Corrado
Marcella
M
Liguori
Francesca
F
Amoroso
Alessandro
A
Fucci
Laura
L
Branno
Margherita
M
D000595:Amino Acid Sequence; D000818:Animals; D004247:DNA / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000033:anatomy & histology / Q000502:physiology; D004720:Endonucleases / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D017403:In Situ Hybridization; D007438:Introns / Q000235:genetics*; D008297:Male; D008780:Methyltransferases / Q000145:classification / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016366:Open Reading Frames / Q000235:genetics*; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D012617:Sea Urchins / Q000196:embryology / Q000201:enzymology* / Q000235:genetics*; D016415:Sequence Alignment
D011994:Recombinant Proteins; D004247:DNA; D008780:Methyltransferases; D004720:Endonucleases