title: Comparative analysis of more than 3000 sequences reveals the existence of two pseudoknots in area V4 of eukaryotic small subunit ribosomal RNA.
abstract: The secondary structure of V4, the largest variable area of eukaryotic small subunit ribosomal RNA, was re-examined by comparative analysis of 3253 nucleotide sequences distributed over the animal, plant and fungal kingdoms and a diverse set of protist taxa. An extensive search for compensating base pair substitutions and for base covariation revealed that in most eukaryotes the secondary structure of the area consists of 11 helices and includes two pseudoknots. In one of the pseudoknots, exchange of base pairs between the two stems seems to occur, and covariation analysis points to the presence of a base triple. The area also contains three potential insertion points where additional hairpins or branched structures are present in a number of taxa scattered throughout the eukaryotic domain.
authors.affiliation: Departement Biochemie, Universiteit Antwerpen (UIA), Universiteitsplein 1, B 2610 Antwerpen, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Wuyts
authors.forename: P
authors.initials: P
authors.lastname: De Rijk
authors.forename: Y
authors.initials: Y
authors.lastname: Van de Peer
authors.forename: G
authors.initials: G
authors.lastname: Pison
authors.forename: P
authors.initials: P
authors.lastname: Rousseeuw
authors.forename: R
authors.initials: R
authors.lastname: De Wachter
mesh_terms: D001483:Base Sequence; D005057:Eukaryotic Cells / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009690:Nucleic Acid Conformation; D012335:RNA, Ribosomal / Q000737:chemistry / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
chemical_list: D012335:RNA, Ribosomal