Timeline for Were nicotinic acid/amide or flavin nucleotides ever part of primary RNA sequence?
Current License: CC BY-SA 4.0
15 events
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| Mar 2, 2021 at 17:26 | comment | added | David | Mike. I'd like to discuss this sort of question, but I have been rather busy over the last few months and am only just re-engaging with the list again in a small way. I am still quite busy and have some other questions here that I need to tidy up loose ends on. I would prefer to wait until I have time to do some reading in this area and then post a question that I feel can generate some good answers. (The great thing about being a scientist is that you never retire. It's just that there comes a time when people aren't paying you any more.) | |
| Mar 2, 2021 at 14:43 | comment | added | Mike Serfas | @David: It sounds like you have some useful thoughts to contribute regarding the evolution. I have trouble deciding what to make of such data. Does the metabolic relationship with tryptophan mean that nicotinic acid evolved from it, or the reverse? If methyltransferases act on nicotinamide and RNA, but they're not closely related, what does that mean? I'm not sure how to get to a conclusion from this sort of information. | |
| Mar 2, 2021 at 12:40 | review | Close votes | |||
| Mar 4, 2021 at 21:58 | |||||
| Mar 2, 2021 at 12:20 | comment | added | David | As you will. I will refrain from commenting on your idea for fear of causing offence, but I do suggest that rather than focussing on chemistry in isolation you consider the evolutionary sequence of events that your idea would entail and attempt to find out what others have written on this topic. | |
| Mar 2, 2021 at 11:30 | comment | added | Mike Serfas | @David: I think a question of that type would be called "unfocused", and in any case, is a different question. How do I ask about whether the RNA world had this range of catalytic activity - without asking it? I think this is already open to a variety of answers and can be answered in the negative as well as the positive. | |
| Mar 2, 2021 at 11:22 | comment | added | David | A way of resolving the problem would be to rephrase the question to allow a variety of answers, not just the one you have in mind. This would be in of the type "NAD and FADH have adenine nucleotide components which are not involved in the redox reactions — show structures — Why?" You could then answer your own question with your idea, which could be subject to the usual criticism in the form of votes and comments. I could add mine. This would be a bit hard on @WYSIWYG who has just answered your question, but he might consider going along with it. | |
| Mar 2, 2021 at 11:22 | comment | added | Mike Serfas | @WYSIWYG: They are useful for your answer, since they show that the NAD isn't excessively reactive in the context of a longer RNA sequence. | |
| Mar 2, 2021 at 11:18 | comment | added | David | There are two reasons that I think this question off-topic. The first is that although you have asked for chemical arguments, answers are likely to be matters of opinion. The second is that it does not really conform to the question and answer format of this site, but is more to the discouraged type "I have this idea, am I right?". The way I see of resolving this (because I find the topic interesting) is given in the following comment. | |
| Mar 2, 2021 at 10:15 | answer | added | WYSIWYG | timeline score: 5 | |
| Mar 2, 2021 at 9:20 | comment | added | WYSIWYG | There are NAD capped RNAs [1,2] but that's not what you are asking, right? | |
| Mar 2, 2021 at 9:00 | history | tweeted | twitter.com/StackBiology/status/1366674682183897088 | ||
| Mar 2, 2021 at 0:35 | comment | added | Mike Serfas | Your thoughts shouldn't be off topic - if you can make a good case for late evolution of NADH and FADH2, then it would rule out the idea. But to my eye, nicotinamide and 5,6-dimethylbenzimidazole don't seem any more different from purines and pyrimidines than those two are from each other. (I'm not claiming to know what they would base pair with) | |
| Mar 2, 2021 at 0:26 | history | edited | Mike Serfas | CC BY-SA 4.0 |
Sorry, quinoline wasn't mentioned later, let's focus a little better
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| Mar 1, 2021 at 20:51 | comment | added | David | Have you searched the literature relating to thoughts on the adenine nucleotide components of NAD and FAD? I am not familiar with this myself, but it clearly must be extensive. My own thoughts on the subject (probably off-topic here) do not include your suggestion of these having been "bases". Nicotinamide and flavin do not look remotely like the bases, have no obvious "pair", and are essentially later oxidising agents to the likely more ancient Fe–S electron redox centres. If they arose to supply the redox function which ribozymes lack, how might they bind to the latter? | |
| Mar 1, 2021 at 17:48 | history | asked | Mike Serfas | CC BY-SA 4.0 |