Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
Permanent URI for this collectionhttps://hdl.handle.net/11147/7148
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Article Citation - WoS: 38Citation - Scopus: 36Structural Studies of Geosmin Synthase, a Bifunctional Sesquiterpene Synthase With ?? Domain Architecture That Catalyzes a Unique Cyclization-Fragmentation Reaction Sequence(American Chemical Society, 2015) Harris, Golda G.; Lombardi, Patrick M.; Pemberton, Travis A.; Matsui, Tsutomu; Weiss, Thomas M.; Cole, Kathryn E.; Köksal, Mustafa; Murphy, Frank V.; Vedula, L. Sangeetha; Chou, Wayne K. W.; Cane, David E.; Christianson, David W.Geosmin synthase from Streptomyces coelicolor (ScGS) catalyzes an unusual, metal-dependent terpenoid cyclization and fragmentation reaction sequence. Two distinct active sites are required for catalysis: the N-terminal domain catalyzes the ionization and cyclization of farnesyl diphosphate to form germacradienol and inorganic pyrophosphate (PPi), and the C-terminal domain catalyzes the protonation, cyclization, and fragmentation of germacradienol to form geosmin and acetone through a retro-Prins reaction. A unique αα domain architecture is predicted for ScGS based on amino acid sequence: each domain contains the metal-binding motifs typical of a class I terpenoid cyclase, and each domain requires Mg2+ for catalysis. Here, we report the X-ray crystal structure of the unliganded N-terminal domain of ScGS and the structure of its complex with three Mg2+ ions and alendronate. These structures highlight conformational changes required for active site closure and catalysis. Although neither full-length ScGS nor constructs of the C-terminal domain could be crystallized, homology models of the C-terminal domain were constructed on the basis of 36% sequence identity with the N-terminal domain. Small-angle X-ray scattering experiments yield low-resolution molecular envelopes into which the N-terminal domain crystal structure and the C-terminal domain homology model were fit, suggesting possible αα domain architectures as frameworks for bifunctional catalysis. © 2015 American Chemical Society.Article Citation - WoS: 44Citation - Scopus: 46A Rhodamine Based "turn-On" Chemodosimeter for Monitoring Gold Ions in Synthetic Samples and Living Cells(Royal Society of Chemistry, 2013) Emrullahoğlu, Mustafa; Karakuş, Erman; Üçüncü, MuhammedA rhodamine-based fluorescent probe, functionalized with an alkyne moiety, shows highly selective recognition towards Au(i) and Au(iii) ions over other metal ions. Probe 1 is successfully employed for the determination of residual gold species in synthetic samples and monitoring the accumulation of gold ions in living cells.Article Citation - WoS: 59Citation - Scopus: 59Gold(i)/Zn(ii) Catalyzed Tandem Hydroamination/Annulation Reaction of 4-Yne(Royal Society of Chemistry, 2010) Demir, Ayhan S.; Emrullahoğlu, Mustafa; Buran, KeremThe tandem hydroamination-annulation reaction of 4-pentyne-nitriles in the presence of amine nucleophiles and a cooperatively operating catalyst system, consisting of Ph3PAuCl and Zn(ClO4)2, provides an efficient route to 2-aminopyrroles. Two regioisomeric 2-aminopyrroles were formed in moderate to good yields. © 2010 The Royal Society of Chemistry.