title: Iminodiacetic-phosphoramidates as metabolic prototypes for diversifying nucleic acid polymerization in vivo.
abstract: Previous studies in our laboratory proved that certain functional groups are able to mimic the pyrophosphate moiety and act as leaving groups in the enzymatic polymerization of deoxyribonucleic acids by HIV-1 reverse transcriptase. When the potential leaving group possesses two carboxylic acid moieties linked to the nucleoside via a phosphoramidate bond, it is efficiently recognized by this error-prone enzyme, resulting in nucleotide incorporation into DNA. Here, we present a new efficient alternative leaving group, iminodiacetic acid, which displays enhanced kinetics and an enhanced elongation capacity compared to previous results obtained with amino acid deoxyadenosine phosphoramidates. Iminodiacetic acid phosphoramidate of deoxyadenosine monophosphate (IDA-dAMP) is processed by HIV-1 RT as a substrate for single nucleotide incorporation and displays a typical Michaelis-Menten kinetic profile. This novel substrate also proved to be successful in primer strand elongation of a seven-base template overhang. Modelling of this new substrate in the active site of the enzyme revealed that the interactions formed between the triphosphate moiety, magnesium ions and enzyme's residues could be different from those of the natural triphosphate substrate and is likely to involve additional amino acid residues. Preliminary testing for a potential metabolic accessibility lets us to envision its possible use in an orthogonal system for nucleic acid synthesis that would not influence or be influenced by genetic information from the outside.
authors.affiliation: Katholieke Universiteit Leuven, Rega Institute for Medical Research, Laboratory of Medicinal Chemistry, Minderbroedersstraat 10, 3000 Leuven, Belgium.
authors.forename: Anne
authors.initials: A
authors.lastname: Giraut
authors.forename: Xiao-ping
authors.initials: XP
authors.lastname: Song
authors.forename: Matheus
authors.initials: M
authors.lastname: Froeyen
authors.forename: Philippe
authors.initials: P
authors.lastname: Marlière
authors.forename: Piet
authors.initials: P
authors.lastname: Herdewijn
mesh_terms: D000249:Adenosine Monophosphate / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis* / Q000737:chemistry; D005998:Glycine / Q000031:analogs & derivatives* / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism; D054303:HIV Reverse Transcriptase / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D008958:Models, Molecular
chemical_list: C549539:deoxyadenosine monophosphate iminodiacetic acid phosphoramidate; D000249:Adenosine Monophosphate; D004247:DNA; C514824:reverse transcriptase, Human immunodeficiency virus 1; D054303:HIV Reverse Transcriptase; D005998:Glycine