TY - JOUR
T1 - Modified bases in tRNA
T2 - The structures of 5-carbamoylmethyl- and 5-carboxymethyl uridine
AU - Berman, Helen M.
AU - Marcu, Deborah
AU - Narayanan, Poojappan
AU - Fissekis, John D.
AU - Lipnick, Robert L.
N1 - Funding Information:
ACKNOWLEDGEMENTS This research was supported by grants GM 21589, CA 06927, RR 05539, CA 16191, CA 08748 and by an appropriation from the Commonwealth of Pennsylvania.
PY - 1978/3
Y1 - 1978/3
N2 - The crystal structures of two nucleosides, 5-carbamoylmethyluridine (1) and 5-carboxyinethyluridine (2), were determined from three-dimensional x-Ray diffraction data, and refined to R=0.036 and R=0.047, respectively. Compound 1 is in the C3′ -endo conformation with X= +5.2° (anti), ψ∞= +63.4° and ψ∞= +180.0° (tt); 2 is in the C2′-endo conformation with X= +49.4° (anti), ψ∞= -60.5° and ψ∞= +60.0° (gg). For each derivative, the plane of the side chain substituent is skewed with respect to the plane of the nucleobase; for 1, the carboxamide group is on the same side of the uracil plane vis a vis the ribose ring; for 2, the carboxyl group is on the opposite side of this plane. No base pairing is observed for either structure. Incorporation of structure 1 into a 3′-stacked tRNA anticodon appears to place 08 within hydrogen bonding istance of the 02′ hydroxyl of ribose 33, which may limit the ability of such a molecule of tRNA to "wobble".
AB - The crystal structures of two nucleosides, 5-carbamoylmethyluridine (1) and 5-carboxyinethyluridine (2), were determined from three-dimensional x-Ray diffraction data, and refined to R=0.036 and R=0.047, respectively. Compound 1 is in the C3′ -endo conformation with X= +5.2° (anti), ψ∞= +63.4° and ψ∞= +180.0° (tt); 2 is in the C2′-endo conformation with X= +49.4° (anti), ψ∞= -60.5° and ψ∞= +60.0° (gg). For each derivative, the plane of the side chain substituent is skewed with respect to the plane of the nucleobase; for 1, the carboxamide group is on the same side of the uracil plane vis a vis the ribose ring; for 2, the carboxyl group is on the opposite side of this plane. No base pairing is observed for either structure. Incorporation of structure 1 into a 3′-stacked tRNA anticodon appears to place 08 within hydrogen bonding istance of the 02′ hydroxyl of ribose 33, which may limit the ability of such a molecule of tRNA to "wobble".
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U2 - 10.1093/nar/5.3.893
DO - 10.1093/nar/5.3.893
M3 - Article
C2 - 643621
AN - SCOPUS:0017839337
VL - 5
SP - 893
EP - 903
JO - Nucleic Acids Research
JF - Nucleic Acids Research
SN - 0305-1048
IS - 3
ER -