title: Structure of 2,4-diaminopyrimidine-theobromine alternate base pairs.
abstract: We report the structure of clusters of 2,4-diaminopyrimidine with 3,7-dimethylxanthine (theobromine) in the gas phase determined by IR-UV double resonance spectroscopy in both the near-IR and mid-IR regions in combination with ab initio computations. These clusters represent potential alternate nucleobase pairs, geometrically equivalent to guanine-cytosine. We have found the four lowest energy structures, which include the Watson-Crick base pairing motif. This Watson-Crick structure has not been observed by resonant two-photon ionization (R2PI) in the gas phase for the canonical DNA base pairs.
authors: Department of Chemistry, Stanford University, Stanford, California 94305-5080, United States.
authors: Zsolt
authors: Z
authors: Gengeliczki
authors: Michael P
authors: MP
authors: Callahan
authors: Martin
authors: M
authors: Kabeláč
authors: Anouk M
authors: AM
authors: Rijs
authors: Mattanjah S
authors: MS
authors: de Vries
mesh_terms: D020029:Base Pairing; D004247:DNA / Q000737:chemistry*; D015394:Molecular Structure; D011743:Pyrimidines / Q000737:chemistry*; D011789:Quantum Theory; D013805:Theobromine / Q000737:chemistry*
chemical_list: D011743:Pyrimidines; C017205:2,4-diaminopyrimidine; D004247:DNA; D013805:Theobromine