NBME 23 Methylase (NBME Answers)

NBME 23 Answers ↦

nbme23/Block 1/Question#16 (62.2 difficulty score)
Physical analysis of the isolated genomic DNA ...
Methylase🔍
tags: biochem restriction_enzymes

+9
submitted by thomasalterman(147),

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latMhsyee ealsmyhtte ND,A nikamg hte DAN tanrisets to noicrtsetir eucdonlnaesse

*mhapjtudtYv./iis3ryrt.fl/ece:ms2l_tot4eunri.hLU7tGvdgLtoRmnoZewzGvffPrsT4xzKctTp/ndj

+9
submitted by imgdoc(132),

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sEanltpxoina fro hsit ear oot lmccaeo.tidp nhkiT fo ti eilk ts:ih

eYou'v otg a peeci of meaudtt NDA that is eabl ot be tidgdsee by a esnitrocitr udseaceeonln, htta aemns het DAN asw aclansrtnioiprlty alleiaavb ot iengb wth.i KAA it swa otn ,eatldheytm eebcusa sa we kon,w hmtynlaeoti = cetrormitheoahn hwcih is riytllnircatasnpo int.cavei tath msnae lemeahtsy wsa udtmtae

ylnO rheto sabiplule seawrn wsa NaD,se nda if ti asw daeuttm it duolw eb tnviaec,i ont cotevvaire.

djeffs1 I mean sure... but this is a prokaryote... +

+4
submitted by defalty98(3),

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Why are ew plctnocagiim ntghi?s ghaenC in het ebsas lwil retdyos the nmicrpdoail neqcseeu eeqirdur rfo nay nsrrciitoet eslunodeeacn to ko.wr oettaynMilh is the lnoy tipono htta saemk es.sne

arcanumm This makes sense have reading what your comment. I overlooked this and just assumed the GATC was a mutation that allowed the restriction enzyme to work on the mutant only. +2

arcanumm it makes even more sense when looking at "numerous small fragments." Methylation is truly the obvious answer here in retrospect. +1

bgiri DNAse can also cause a change in base by breaking down dna at the GATC sequence? +

almondbreeze @bgiri Had the same reasoning - according to wiki, DNase catalyzes the hydrolytic cleavage of phosphodiester linkages in the DNA backbone, thus degrading DNA. +

+4
submitted by pk33(5),

In prokayotes Normally methylase adds methyl group to certain base(adenine) so restriction endonuclease can not recognize this site. If there is a mutation in methylase enzyme it can't add methyl group to adenine so restriction endonuclease can recognize it and can cleave it.

+4
submitted by stinkysulfaeggs(91),

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eM gadeirn sith uotisqne semt: ..o.d.. ouy emna hihcw fo eth fnlgiloow EMNYE?SZ

+0
submitted by consistentwrongdoer3(17),

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hWy sdeo hloeamtityn csaeu lsso of sesrcentia to TCGA nrirtcoteis ?enleoeacusnd esoD isht eahv ot do tiwh eittmylonah of U ot ?T

methylased GATC related to methylase --> https://en.wikipedia.org/wiki/Dam_methylase +8

sympathetikey Dam methylase, alright +2

yogi https://www.neb.com/tools-and-resources/usage-guidelines/dam-and-dcm-methylases-of-e-coli +2