| 词条 | SMK box riboswitch |
| 释义 |
| Name = SMK box translational riboswitch | image = SMK riboswitch structure.jpg | width = 200px | caption = A representation of the SMK box translational riboswitch secondary structure including a colour scheme that indicates the degree of sequence conservation. | Symbol = SMK_box_riboswitch | AltSymbols = SAM-III, SMK | Rfam = RF01767 | RNA_type = Riboswitch | Tax_domain = Firmicutes | CAS_number = | EntrezGene = | HGNCid = | OMIM = | PDB = {{PDB3|3e5f}} {{PDB3|3e5e}} {{PDB3|3e5c}} | RefSeq = | Chromosome = | Arm = | Band = | LocusSupplementaryData = }} The SMKbox riboswitch (also known as SAM-III) is a RNA element that regulates gene expression in bacteria.[2][3] The SMK box riboswitch is found in the 5' UTR of the MetK gene in lactic acid bacteria. The structure of this element changes upon binding to S-adenosyl methionine (SAM) to a conformation that blocks the shine-dalgarno sequence and blocks translation of the gene. There are other known SAM-binding riboswitches such as SAM-I and SAM-II, but these appear to share no similarity in sequence or structure to SAM-III. StructureThe crystal structure of the riboswitch from E. faecalis was solved by X-ray crystallography. The structure showed that the most conserved nucleotides involved in SAM binding were organised around a junction between three helices.[1] In some species there are large insertions of up to 210 nucleotides within this structure. See also
References1. ^1 {{cite journal |doi=10.1038/nsmb.1494 |vauthors=Lu C, Smith AM, Fuchs RT, Ding F, Rajashankar K, Henkin TM, Ke A |title=Crystal structures of the SAM-III/S(MK) riboswitch reveal the SAM-dependent translation inhibition mechanism. |journal=Nat Struct Mol Biol |volume=15 |issue=10 |pages=1076–83 |year=2008 |pmid=18806797 |pmc=3467307}} 2. ^{{cite journal |vauthors=Fuchs RT, Grundy FJ, Henkin TM |title=The S(MK) box is a new SAM-binding RNA for translational regulation of SAM synthetase |journal=Nat. Struct. Mol. Biol. |volume=13 |issue=3 |pages=226–33 |year=2006 |pmid=16491091 |doi=10.1038/nsmb1059}} 3. ^{{cite journal |vauthors=Fuchs RT, Grundy FJ, Henkin TM |title=S-adenosylmethionine directly inhibits binding of 30S ribosomal subunits to the SMK box translational riboswitch RNA |journal=Proc. Natl. Acad. Sci. U.S.A. |volume=104 |issue=12 |pages=4876–80 |year=2007 |pmid=17360376 |doi=10.1073/pnas.0609956104 |pmc=1829232}} External links
2 : Cis-regulatory RNA elements|Riboswitch |
| 随便看 |
|
开放百科全书收录14589846条英语、德语、日语等多语种百科知识，基本涵盖了大多数领域的百科知识，是一部内容自由、开放的电子版国际百科全书。