tag:blogger.com,1999:blog-32079676.post791907667398122143..comments2024-02-13T21:22:02.522-08:00Comments on RRResearch: Purine regulation of competenceRosie Redfieldhttp://www.blogger.com/profile/06807912674127645263noreply@blogger.comBlogger1125tag:blogger.com,1999:blog-32079676.post-73045492571029156292010-03-24T00:59:54.817-07:002010-03-24T00:59:54.817-07:00So... genotypes:
wt
purR-
sxy-1
purR- sxy-1
And c...So... genotypes:<br />wt<br />purR-<br />sxy-1<br />purR- sxy-1<br /><br />And conditions:<br />MIV ± 5 mM purines<br />sBHI time course ± cAMP<br /><br />Assays:<br />1st: Transformations<br />2nd: Expression levels via lacZ, RT PCR, and Western (CRP-N, CRP-S, purine genes)<br />2nd: If the rec-2 hypothesis has legs, functional assays of uptake and translocation<br /><br />I’m still not so sure about the constitutive purine pools in purR-. Sure, purine biosynthesis genes may be constitutively expressed in the mutant, but presumably the stem-loop is not responding to biosynthesis of purines, but to their concentration in the cell. Since the purR- mutation has no effect on competence in MIV, then surely [purine] is not high enough (independent of the transcription of the biosynthetic genes) to repress competence. And since adding purines to MIV still represses competence of purR- cells, we know that the putative sxy regulation by purines isn’t through PurR itself. <br /><br />On the other hand, if we take you and the former grad student’s data as collectively correct, then in late-log sBHI, it would seem [purines] in the purR- mutant are high enough to repress competence.Changhttps://www.blogger.com/profile/12291718994939895064noreply@blogger.com