000			01816nam a2200181Ia 4500
003			MX-MdCICY
005			20250625162454.0
040			_cCICY
090			_aB-20753
245	1	0	_aA restriction enzyme from Hemophilus influenzae: II. Base sequence of the recognition site
490	0		_vJournal of Molecular Biology, 51(2), p.393-409, 1970
520	3		_aHemophilus influenzae strain Rd contains an enzyme, endonuolease R, which specifically degrades foreign DNA. With phage T7 DNA as substrate the endonuclease introduces a limited number (about 40)double-strand breaks (5?-phosphoryl, 3?-hydroxyl). The limit product has an average length of about 1000 nucleotide pairs and contains no single-strand breaks. We have explored the nucleotide sequences at the 5?-ends of the limit product by labeling the 5?- phosphoryl groups (using polynucleotide kinase)and characterizing the labeled fragments released by various nucleases. Two classes of 5?-terminal sequences were obtained: pApApCpNp . (60 percent)and pGpApCpNp . (40 percent), where N indicates that the base in the 4th position is not unique. The dinucleoside monophosphates at the 3?-ends were isolated after micrococcal nuclease digestion of the limit product and identified as TpT(60 percent)and TpC (40 percent). We conclude that endonuclease R of H. influenzae recognizes the following specific nucleotide sequence: 5? . pGpTpPy ¦pPupApCp . 3? 3? . pCpApPup ¦PypTpGp . 5? The implications of the twofold rotational symmetry of this sequence are discussed.
700	1	2	_aKelly Jr, T. J.
700	1	2	_aSmith, H. O.
856	4	0	_uhttps://drive.google.com/file/d/1F-5rnj_Lck5d8EbqYfpeTxB20srjhLo_/view?usp=drivesdk _zPara ver el documento ingresa a Google con tu cuenta: @cicy.edu.mx
942			_2Loc _cREF1
008			250602s9999 xx |||||s2 |||| ||und|d
999			_c54834 _d54834