title: Synthesis of alanyl nucleobase amino acids and their incorporation into proteins.
abstract: Proteins which bind to nucleic acids and regulate their structure and functions are numerous and exceptionally important. Such proteins employ a variety of strategies for recognition of the relevant structural elements in their nucleic acid substrates, some of which have been shown to involve rather subtle interactions which might have been difficult to design from first principles. In the present study, we have explored the preparation of proteins containing unnatural amino acids having nucleobase side chains. In principle, the introduction of multiple nucleobase amino acids into the nucleic acid binding domain of a protein should enable these modified proteins to interact with their nucleic acid substrates using Watson-Crick and other base pairing interactions. We describe the synthesis of five alanyl nucleobase amino acids protected in a fashion which enabled their attachment to a suppressor tRNA, and their incorporation into each of two proteins with acceptable efficiencies. The nucleobases studied included cytosine, uracil, thymine, adenine and guanine, i.e. the major nucleobase constituents of DNA and RNA. Dihydrofolate reductase was chosen as one model protein to enable direct comparison of the facility of incorporation of the nucleobase amino acids with numerous other unnatural amino acids studied previously. The Klenow fragment of DNA polymerase I was chosen as a representative DNA binding protein whose mode of action has been studied in detail.
authors.affiliation: Biodesign Center for BioEnergetics and School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA.
authors.forename: Poulami
authors.initials: P
authors.lastname: Talukder
authors.affiliation: Biodesign Center for BioEnergetics and School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA.
authors.forename: Larisa M
authors.initials: LM
authors.lastname: Dedkova
authors.affiliation: Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Ellington
authors.affiliation: Biodesign Center for BioEnergetics and School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA.
authors.forename: Petro
authors.initials: P
authors.lastname: Yakovchuk
authors.affiliation: Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Jaebum
authors.initials: J
authors.lastname: Lim
authors.affiliation: Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA.
authors.forename: Eric V
authors.initials: EV
authors.lastname: Anslyn
authors.affiliation: Biodesign Center for BioEnergetics and School of Molecular Sciences, Arizona State University, Tempe, AZ 85287, USA. Electronic address: Sidney.Hecht@asu.edu.
authors.forename: Sidney M
authors.initials: SM
authors.lastname: Hecht
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000235:genetics; D003062:Codon; D004256:DNA Polymerase I / Q000235:genetics; D004926:Escherichia coli; D011687:Purines / Q000138:chemical synthesis*; D011744:Pyrimidinones / Q000138:chemical synthesis*; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D012343:RNA, Transfer / Q000138:chemical synthesis / Q000235:genetics; D013762:Tetrahydrofolate Dehydrogenase / Q000737:chemistry* / Q000235:genetics; D046249:Transfer RNA Aminoacylation
chemical_list: D003062:Codon; D011687:Purines; D011744:Pyrimidinones; D012333:RNA, Messenger; D012343:RNA, Transfer; D013762:Tetrahydrofolate Dehydrogenase; D004256:DNA Polymerase I; D000409:Alanine
keywords: DNA polymerase I; DNA(_)protein interaction; N-Boc-L-serine β-lactone; Nucleobases