SAM-II riboswitch

The SAM-II riboswitch is a RNA element found predominantly in alpha-proteobacteria that binds S-adenosyl methionine (SAM).[1] Its structure and sequence appear to be unrelated to the SAM riboswitch found in Gram-positive bacteria. This SAM riboswitch is located upstream of the metA and metC genes in Agrobacterium tumefaciens, and other methionine and SAM biosynthesis genes in other alpha-proteobacteria. Like the other SAM riboswitch, it probably functions to turn off expression of these genes in response to elevated SAM levels. A significant variant of SAM-II riboswitches was found in Pelagibacter ubique and related marine bacteria and called SAM-V.[2] Also, like many structured RNAs, SAM-II riboswitches can tolerate long loops between their stems.[3]

SAM riboswitch (alpha-proteobacteria)
Predicted secondary structure and sequence conservation of SAM_alpha
Identifiers
SymbolSAM_alpha
RfamRF00521
Other data
RNA typeCis-reg; riboswitch
Domain(s)Bacteria
GO0045814
SO0000035
PDB structuresPDBe

Structure

The SAM-II riboswitch is short with less than 70 nucleotides and is structurally relatively simple being composed of a single hairpin and a pseudoknot.

gollark: Ah, I ¢.
gollark: Oh, cool, how'd it work?
gollark: Also,- offload all actual computation to C L O U D, make "OS" on client just be a dumb terminal.
gollark: The only working ways to do sandboxing:- override `fs`- disallow access to actual shell like ShutdownOS does
gollark: Look, aliases are easily overcome.

See also

References
  1. Corbino KA, Barrick JE, Lim J, et al. (2005). "Evidence for a second class of S-adenosylmethionine riboswitches and other regulatory RNA motifs in alpha-proteobacteria". Genome Biol. 6 (8): R70. doi:10.1186/gb-2005-6-8-r70. PMC 1273637. PMID 16086852.
  2. Poiata E, Meyer MM, Ames TD, Breaker RR (November 2009). "A variant riboswitch aptamer class for S-adenosylmethionine common in marine bacteria". RNA. 15 (11): 2046–2056. doi:10.1261/rna.1824209. PMC 2764483. PMID 19776155.
  3. Weinberg Z, Wang JX, Bogue J, et al. (March 2010). "Comparative genomics reveals 104 candidate structured RNAs from bacteria, archaea and their metagenomes". Genome Biol. 11 (3): R31. doi:10.1186/gb-2010-11-3-r31. PMC 2864571. PMID 20230605.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.