Talk:Selenocysteine

Thanks!

Just wanted to say Thanks! to all the people who worked on this article. It does an excellent job of describing a fascinating and complicated topic (to somebody with only a passing familiarity with the subject). --RoySmith 00:20, 20 Jun 2005 (UTC)

Suggested Additions: Comparitive Activity

One thing that would help expand this article is a discussion of the enzymatic activity of Sec. How does it differ from normal Cys in function? What sort of reactions require Se as a catalyst? —Preceding unsigned comment added by Quantum7 (talk • contribs) 21:21, 29 February 2008 (UTC)

Definitely! --Belg4mit (talk) 15:24, 10 July 2008 (UTC)

The article indeed shows promise but it really fails to provide general references vs the current hyperspecialized literature. WE is not a technical review journal, so comparisons with cys would ideally entail summaries of textbooky stuff, and not extrapolations or interpretations. Hopefully such info can be located for the future expansion. Also some recent work has discussed the occurrence in nature of mixed RSSER' species.--Smokefoot (talk) 17:15, 10 July 2008 (UTC)

One major class of selenoenzymes are the iodinases and deiodinases for thyroid hormone synthesis and conversion. (Swfowkes (talk) 01:02, 23 May 2019 (UTC))

Use in the body

This is going to sound crazy- but I have to say it. I received a message from God relating to this compound. The message was that this is a necessary compound in the formation of blood vessels. There needs to be medical research done on vascular problems and lack of Selenocysteine. Selenocysteine is necessary to be present to metabolize selenium in blood vessel formation. New blood vessels forming need to have this in order to harden and form their structure. I can't really say anything more- except that somewhere a medical researcher is supposed to read this, and start doing that kind of research. Jim E85 (talk) 14:32, 14 February 2010 (UTC)

Clarification or correction needed

"In bacteria, the SECIS element is located immediately following the UGA codon within the reading frame for the selenoprotein"

This contradicts what I was told in a class recently, which admittedly is not always the best source of information. I was told that the mRNA molecule (in E. coli) has a SECIS element 3' of the "real" stop codon (UAG? in all cases?) and that ALL UGAs upsteam (5') of this element (and 3' to the RBS and start codon) are replaced with Seleno-cysteine.

However, the wiki-stated model does agree with a fairly old article biochemistry-speaking: Molecular Microbiology {1991) 5(3), 515-520 Selenocysteine: the 21st amino acid A. Bock,* K. Forchhammer, J. Heider, W. Leinfelder, G. Sawers, B. Veprek and F. Zinoni

Which specifies the recognized stem-loop be immediately 3' to the sense UGA codon. This would suggest that either a) this stem loop has a very promiscuous recognition sequence Vis. SECIS element binding protein(s) b) there are a small and finite number of permutations of amino acids that can immediately follow selenocysteine in the protein c) the mRNA is spliced [and I believe only tRNA is known to be spliced in bacteria, and rarely at that] to remove the stem loop d) the SelCys has to be the carboxy terminal amino acid (and one of the complex of stem loop binding proteins has to also be a release factor for translation) or E) the protein is post-translationally modified to remove the "signal tag". Has there been any further research to clarify this? I'm assuming D is out and C seems unlikely as well (and E may require an overly complex recognition if the amino acid sequence varies at all). So, is the true answer A, B, E what I was told in class, or something I'm failing to consider? — Preceding unsigned comment added by 146.186.85.64 (talk) 16:55, 3 October 2011 (UTC)

Theresa Stadtman?

Her qualification consist of being married to biochemist??? A quick google shows that she is a PhD and a biochemist in her own right. Is there something I am missing? Kortoso (talk) 00:08, 14 December 2013 (UTC)

Nice point. I just made a minor change that helps, but probably doesn't go far enough. I'm new to editing so I didn't want to get too ambitious. Hopefully someone else can help finish. From what I can gather, they were a research team, so it isn't irrelevant who she was married to, but as you mention, it's sort of silly to present that as a credential. Scaldwell17 (talk) 23:27, 15 December 2013 (UTC)

Thank you. She doesn't have her own entry, and perhaps this will be ameliorated. Her husband was apparently an important member of the team, but she's gotten the credit. I'll see if I can come up with an appropriate wording. Kortoso (talk) 17:52, 16 December 2013 (UTC)

Methanogen

Found this: Selenocysteine, Pyrrolysine, and the Unique Energy Metabolism of Methanogenic Archaea

Methanogenic archaea are a group of strictly anaerobic microorganisms characterized by their strict dependence on the process of methanogenesis for energy conservation. Among the archaea, they are also the only known group synthesizing proteins containing selenocysteine or pyrrolysine. All but one of the known archaeal pyrrolysine-containing and all but two of the confirmed archaeal selenocysteine-containing protein are involved in methanogenesis. Synthesis of these proteins proceeds through suppression of translational stop codons but otherwise the two systems are fundamentally different. This paper highlights these differences and summarizes the recent developments in selenocysteine- and pyrrolysine-related research on archaea and aims to put this knowledge into the context of their unique energy metabolism.

Worthy of inclusion? Kortoso (talk) 16:57, 10 September 2015 (UTC)

References

Which Species?

The article claims that members of all three biological domains use it, but the only species mentioned to have selenocysteine is Homo sapiens. Another article says Desulfitobacterium halfniensi uses it. Is there a list somewhere of other species that can be added to this article? 2601:441:4400:1740:7C83:2209:45EF:5A30 (talk) 22:37, 11 January 2022 (UTC)