title: Recognition of Artificial Nucleobases by E. coli Purine Nucleoside Phosphorylase versus its Ser90Ala Mutant in the Synthesis of Base-Modified Nucleosides.
abstract: A wide range of natural purine analogues was used as probe to assess the mechanism of recognition by the wild-type (WT) E. coli purine nucleoside phosphorylase (PNP) versus its Ser90Ala mutant. The results were analyzed from viewpoint of the role of the Ser90 residue and the structural features of the bases. It was found that the Ser90 residue of the PNP 1) plays an important role in the binding and activation of 8-aza-7-deazapurines in the synthesis of their nucleosides, 2) participates in the binding of α-D-pentofuranose-1-phosphates at the catalytic site of the PNP, and 3) catalyzes the dephosphorylation of intermediary formed 2-deoxy-α-D-ribofuranose-1-phosphate in the trans-2-deoxyribosylation reaction. 5-Aza-7-deazaguanine manifested excellent substrate activity for both enzymes, 8-amino-7-thiaguanine and 2-aminobenzothiazole showed no substrate activity for both enzymes. On the contrary, the 2-amino derivatives of benzimidazole and benzoxazole are substrates and are converted into the N1- and unusual N2-glycosides, respectively. 9-Deaza-5-iodoxanthine showed moderate inhibitory activity of the WT E. coli PNP, whereas 9-deazaxanthine and its 2'-deoxyriboside are weak inhibitors.
authors.affiliation: Department of Biotechnology, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, RAS, Miklukho-Maklaya 16/10, 117997 GSP, Moscow B-437 (Russian Federation).
authors.forename: Ilja V
authors.initials: IV
authors.lastname: Fateev
authors.affiliation: Department of Biotechnology, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, RAS, Miklukho-Maklaya 16/10, 117997 GSP, Moscow B-437 (Russian Federation).
authors.forename: Maria I
authors.initials: MI
authors.lastname: Kharitonova
authors.affiliation: Department of Biotechnology, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, RAS, Miklukho-Maklaya 16/10, 117997 GSP, Moscow B-437 (Russian Federation).
authors.forename: Konstantin V
authors.initials: KV
authors.lastname: Antonov
authors.affiliation: Department of Biotechnology, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, RAS, Miklukho-Maklaya 16/10, 117997 GSP, Moscow B-437 (Russian Federation).
authors.forename: Irina D
authors.initials: ID
authors.lastname: Konstantinova
authors.affiliation: Department of Biotechnology, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, RAS, Miklukho-Maklaya 16/10, 117997 GSP, Moscow B-437 (Russian Federation).
authors.forename: Vasily N
authors.initials: VN
authors.lastname: Stepanenko
authors.affiliation: Department of Biotechnology, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, RAS, Miklukho-Maklaya 16/10, 117997 GSP, Moscow B-437 (Russian Federation).
authors.forename: Roman S
authors.initials: RS
authors.lastname: Esipov
authors.affiliation: Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, Heisenbergstr. 11, 48149 Münster (Germany).
authors.forename: Frank
authors.initials: F
authors.lastname: Seela
authors.affiliation: University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250 (USA).
authors.forename: Kartik W
authors.initials: KW
authors.lastname: Temburnikar
authors.affiliation: University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, Maryland 21250 (USA).
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Seley-Radtke
authors.affiliation: Institute of Bioorganic Chemistry, National Academy of Sciences, 220141 Minsk, Acad. Kuprevicha 5/2 (Belarus).
authors.forename: Vladimir A
authors.initials: VA
authors.lastname: Stepchenko
authors.affiliation: Institute of Bioorganic Chemistry, National Academy of Sciences, 220141 Minsk, Acad. Kuprevicha 5/2 (Belarus).
authors.forename: Yuri A
authors.initials: YA
authors.lastname: Sokolov
authors.affiliation: Department of Biotechnology, Shemyakin and Ovchinnikov Institute of Bioorganic Chemistry, RAS, Miklukho-Maklaya 16/10, 117997 GSP, Moscow B-437 (Russian Federation).
authors.forename: Anatoly I
authors.initials: AI
authors.lastname: Miroshnikov
authors.affiliation: Institute of Bioorganic Chemistry, National Academy of Sciences, 220141 Minsk, Acad. Kuprevicha 5/2 (Belarus). imikhailopulo@gmail.com.
authors.forename: Igor A
authors.initials: IA
authors.lastname: Mikhailopulo
mesh_terms: D000409:Alanine / Q000031:analogs & derivatives / Q000737:chemistry*; D001483:Base Sequence; D001665:Binding Sites; D002384:Catalysis; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000737:chemistry* / Q000378:metabolism; D007700:Kinetics; D009705:Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism; D011683:Purine-Nucleoside Phosphorylase / Q000138:chemical synthesis* / Q000737:chemistry; D013329:Structure-Activity Relationship
chemical_list: D009705:Nucleosides; D011683:Purine-Nucleoside Phosphorylase; D000409:Alanine
keywords: ab initio calculations; escherichia coli; glycosylation; nucleobases; purine analogues; substrate properties