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| SAM riboswitch (alpha-proteobacteria) |
 |
| Type: |
Cis-reg; riboswitch; |
| 2° structure: |
Predicted; Barrick JE |
| Seed alignment: |
Barrick JE |
| Avg length: |
76.8 nucleotides |
| Avg identity: |
59% |
|
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.
[edit] 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.
[edit] References
- ^ 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. PMID 16086852.
[edit] External links
