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A family of small nucleoplasmic RNAs with common structural features
Author(s) -
Jacob M.,
Lazar E.,
Haendler B.,
Gallinaro H.,
Krol A.,
Branlant C.
Publication year - 1984
Publication title -
biology of the cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.543
H-Index - 85
eISSN - 1768-322X
pISSN - 0248-4900
DOI - 10.1111/j.1768-322x.1984.tb00278.x
Subject(s) - biology , small nucleolar rna , computational biology , microrna , genetics , non coding rna , gene
The four small nucleoplasmic RNAs designated as U1, U2, U4 and U5 RNA have a common structural domain or domain A. It is characterized by the presence of consensus sequence Pu‐A‐(U)5‐G‐Pup in a free single‐stranded region and of the sequence Py‐N‐Py‐Gp in the top loop of a hairpin located at the 3′ end of the free region. Domain A is likely to be involved in a function common to the four small RNAs. Other domains possibly involved in the specific function of U1 and U5 RNAs are also presented. Several molecular forms of a same U RNA may be found in a same cellular type. These variant U RNAs are particularly numerous for U5 RNA. The possible origin of such new molecular forms is discussed in relation to multigene families for U RNAs. U1, U2, U4 and U5 RNAs are capped (with trimethylguanosine) and the consensus sequence for their 6 first nucleotides is A‐(Py)5p. Thus, their 5′ end resembles that of premessenger RNA, also capped (with monomethylguanosine) and bearing A‐(Py)5p. Both classes of RNA are synthesized by RNA polymerase B, but the presence of a “TATA box” upstream of the capsite has not yet been demonstrated for U RNA genes. U1, U2, U4 and U5 RNAs bear a sequence C‐Py‐Pu at their 3′ end or very close to it. This trinucleotide might be part of a site of post‐transcriptional cleavage of U RNA precursors.(ABSTRACT TRUNCATED AT 250 WORDS)