tRNA prefers to kiss.
Six RNA aptamers that bind to yeast phenylalanine tRNA were identified by in vitro selection from a random-sequence pool. The two most abundantly represented aptamers interact with the tRNA anticodon loop, each through a sequence block with perfect Watson-Crick complementarity to the loop. It was possible to truncate one of these aptamers to a simple hairpin loop that forms a classical 'kissing complex' with the anticodon loop. Three other aptamers have nearly complete complementarity to the anticodon loop. The sixth aptamer has two sequence blocks, one complementary to the tRNA T loop and the other to the D loop; this aptamer binds better to a mutant tRNA that disrupts the normal D-loop/T-loop tertiary interaction than to the wild-type tRNA. Selection of complements to tRNA loops occurred despite an attempt to direct binding to tertiary structural features of tRNA. This serves as a reminder of how special the RNA-RNA interactions are that are not based on complementarity. Nonetheless, these aptamers must present the tRNA complement in some special structural context; the simple single-strand complement of the anticodon loop did not bind tRNA effectively.
Scarabino
D
D
EniChem SpA, Istituto Guido Donegani, CNR, Via Ramarini 32, 0016 Monterotondo, Rome, Italy.
Crisari
A
A
Lorenzini
S
S
Williams
K
K
Tocchini-Valentini
G P
GP
D000926:Anticodon; D001483:Base Sequence; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D018075:RNA, Complementary; D012331:RNA, Fungal / Q000737:chemistry / Q000378:metabolism; D012360:RNA, Transfer, Phe / Q000737:chemistry / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics*
D000926:Anticodon; D018075:RNA, Complementary; D012331:RNA, Fungal; D012360:RNA, Transfer, Phe