tag:blogger.com,1999:blog-32079676.post2698972083213571881..comments2024-02-13T21:22:02.522-08:00Comments on RRResearch: Fructose? Why not glucose?Rosie Redfieldhttp://www.blogger.com/profile/06807912674127645263noreply@blogger.comBlogger3125tag:blogger.com,1999:blog-32079676.post-39576976094580447172006-12-07T04:27:00.000-08:002006-12-07T04:27:00.000-08:00Hey Mark, that reminds me, we do have a cAMP indic...Hey Mark, that reminds me, we do have a cAMP indicator strain, made by a former grad student. She fused E. coli's lacZ to a CRP-regulated promoter. As I remember, the signal it produces is VERY weak (less than 50 Miller units even when fully induced), but the differences are significant.<br /><br />But, I don't think I want to take our research into this swamp, at least while I see other questions that I think will be easier to answer.Rosie Redfieldhttps://www.blogger.com/profile/06807912674127645263noreply@blogger.comtag:blogger.com,1999:blog-32079676.post-63904739875436384112006-12-05T18:18:00.000-08:002006-12-05T18:18:00.000-08:00Maybe it has something to do with the environment ...Maybe it has something to do with the environment Haemophilus is in being more constant than the environment E. coli and other relatives are in. Regulation of the sugar uptake and cAMP levels is not as dynamic because the sugars are always around at a semi-constant level (at least constant for bacterial cells)?90% microbehttps://www.blogger.com/profile/10288595333674587852noreply@blogger.comtag:blogger.com,1999:blog-32079676.post-9437949124193578262006-12-04T12:43:00.000-08:002006-12-04T12:43:00.000-08:00Interesting post, Rosie.
I'm not sure that pts is...Interesting post, Rosie.<br /><br />I'm not sure that pts is the only way or even major way to modulate adenylate cyclase activity. Perhaps there are other sensors that kick up the activity of that enzyme. It would be interesting, in your system, to have some kind of cya-lux or cya-lac fusion and determine if other sugars (or other metabolites) impact cya expression.<br /><br />Back in my Sinorhizobium days, we found out that glucose was not the catabolite repressor in that system; dicarboxylates were. And that makes sense since dicarboxylates are the important compound in the symbiosis (despite the fact that sucrose is most of the nodule cytosol).<br /><br />Similarly, we have found out in our odd little bacterium that there are five cya like genes. Hmmm.<br /><br />You have forgotten more about microbial genetics than I will ever know. But I thought I would comment.<br /><br />Best,<br /><br />Mark MartinAnonymousnoreply@blogger.com