SAM-VI is a member of the
riboswitch
In molecular biology, a riboswitch is a regulatory segment of a messenger RNA molecule that binds a small molecule, resulting in a change in production of the proteins encoded by the mRNA. Thus, an mRNA that contains a riboswitch is directly in ...
family. It is predominantly found in ''
Bifidobacterium
''Bifidobacterium'' is a genus of gram-positive, nonmotile, often branched anaerobic bacteria. They are ubiquitous inhabitants of the gastrointestinal tract though strains have been isolated from the vagina and mouth ('' B. dentium'') of mammal ...
'' and exhibits some similarities to the SAM-III (
Smk box) riboswitch class, but lacks most of the highly conserved nucleotides of SAM-III class. SAM-VI
aptamers bind the cofactor
S-adenosylmethinine SAM (a key metabolite in sulphur metabolism) and discriminate strongly against
S-adenosylhomocysteine SAH. The class was discovered by further analysis of Bifido-''meK'' motif RNAs.
See also
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SAM-I riboswitch
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SAM-II riboswitch
The SAM-II riboswitch is a RNA element found predominantly in Alphaproteobacteria that binds S-adenosyl methionine (SAM). Its structure and sequence appear to be unrelated to the SAM riboswitch found in Gram-positive bacteria. This SAM riboswit ...
*
SAM-III riboswitch
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SAM-IV riboswitch
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SAM-V riboswitch
References
{{reflist
Cis-regulatory RNA elements
Riboswitch