SECIS element
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2008-07-06T06:31:29Z
216.9.143.129
added pmids
{{Rfam_box|acc=RF00031|description=SECIS element|abbreviation=SECIS|type=Cis-reg;|avg_length=64.2|avg_identity=43|ss=Published; {{PMID|12458087}}|se=Griffiths-Jones SR|type=Cis-reg;}}
In [[biology]], the '''SECIS element''' (SECIS: '''''se'''leno'''c'''ysteine '''i'''nsertion '''s'''equence'') is an [[cis-regulatory element|RNA element]] around 60 [[nucleotides]] in length that adopts a [[stem-loop]] structure.<ref>{{cite journal | last = Walczak | first = R | coauthors = Westhof E, Carbon P, Krol A | year = 1996 | title = A novel RNA structural motif in the selenocysteine insertion element of eukaryotic selenoprotein mRNAs | journal = RNA | volume = 2 | pages = 367–379 | pmid = 8634917}}</ref> This structural motif (pattern of nucleotides) directs the [[cell (biology)|cell]] to [[translation (biology)|translate]] UGA [[codon]]s as [[selenocysteine]]s. (UGA is normally a [[stop codon]].) SECIS elements are thus a fundamental aspect of [[selenoprotein]]s, which are proteins that include one or more selenocysteine residues.
In [[eubacteria]] the SECIS element appears soon after the UGA codon it affects. In [[archaea]] and [[eukaryote]]s, it occurs in the [[3' UTR]] of an [[mRNA]], and can cause multiple UGA codons within the mRNA to code for selenocysteine. One archaeal SECIS element, in ''[[Methanococcus]],'' is located in the [[5' UTR]].
The SECIS element appears defined by sequence characteristics, i.e. particular nucleotides tend to be at particular positions in it, and a characteristic [[secondary structure]]. The secondary structure is the result of base-pairing of complementary [[RNA]] nucleotides, and causes a hairpin-like structure. The eukaryotic SECIS element includes non-canonical A-G base pairs, which are uncommon in nature, but are critically important to correct SECIS element function. Although the eukaryotic, archaeal and eubacterial SECIS elements each share a general hairpin structure, they are not alignable, e.g. a scheme to recognize eukaryotic SECIS elements will not be able to recognize archaeal SECIS elements.
In [[bioinformatics]], several computer programs have been created that search for SECIS elements within a [[genome]] sequence, based on the sequence and secondary structure characteristics of SECIS elements. These programs have been used in searches for novel selenoproteins.<ref>{{cite journal | last = Lambert | first = A | coauthors = Lescure A, Gautheret D | year = 2002 | title = A survey of metazoan selenocysteine insertion sequences | journal = Biochimie | volume = 84 | pages = 953–959 | pmid = 12458087 | doi = 10.1016/S0300-9084(02)01441-4}}</ref>
===Species distribution===
The SECIS element is found in a wide variety of eukaryotes, prokaryotes and viruses.<ref name="pmid17169995">{{cite journal | author = Mix H, Lobanov AV, Gladyshev VN | title = SECIS elements in the coding regions of selenoprotein transcripts are functional in higher eukaryotes | journal = Nucleic Acids Res. | volume = 35 | issue = 2 | pages = 414–23 | year = 2007 | pmid = 17169995 | doi = 10.1093/nar/gkl1060 | issn = }}</ref><ref name="pmid16766053">{{cite journal | author = Cassago A, Rodrigues EM, Prieto EL, ''et al'' | title = Identification of Leishmania selenoproteins and SECIS element | journal = Mol. Biochem. Parasitol. | volume = 149 | issue = 2 | pages = 128–34 | year = 2006 | pmid = 16766053 | doi = 10.1016/j.molbiopara.2006.05.002 | issn = }}</ref><ref name="pmid15659354">{{cite journal | author = Mourier T, Pain A, Barrell B, Griffiths-Jones S | title = A selenocysteine tRNA and SECIS element in Plasmodium falciparum | journal = RNA | volume = 11 | issue = 2 | pages = 119–22 | year = 2005 | pmid = 15659354 | doi = 10.1261/rna.7185605 | issn = }}</ref><ref name="pmid12458087">{{cite journal | author = Lambert A, Lescure A, Gautheret D | title = A survey of metazoan selenocysteine insertion sequences | journal = Biochimie | volume = 84 | issue = 9 | pages = 953–9 | year = 2002 | pmid = 12458087| doi = 10.1016/S0300-9084(02)01441-4| issn = }}</ref>
==References==
{{reflist|1}}
* {{cite journal | author=G. V. Kryukov, S. Castellano, S. V. Novoselov, A. V. Lobanov, O. Zehtab, R. Guigó, and V. N. Gladyshev | title=Characterization of mammalian selenoproteomes | journal=Science | year=2003 | volume=300 | issue=5624 | pages= 1439–1443 | doi=10.1126/science.1083516 | pmid=12775843}}
* {{cite journal | author=Gregory V. Kryukov and Vadim N. Gladyshev | title=The prokaryotic selenoproteome | journal=EMBO Rep | year=2004 | volume=5 | issue=5 | pages= 538–543 | doi=10.1038/sj.embor.7400126 | pmid=15105824}}
* {{cite journal | author=Alain Krol | title=Evolutionarily different RNA motifs and RNA-protein complexes to achieve selenoprotein synthesis | journal=Biochimie | year=2002 | volume=84 | issue=8 | pages= 765–774 | doi=10.1016/S0300-9084(02)01405-0 | pmid=12457564}}
==External links==
* {{Rfam|id=RF00031|name=SECIS element}}
[[Category:Gene expression]]
[[Category:Cis-regulatory RNA elements]]
[[ca:Element SECIS]]
[[da:SECIS-element]]