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981.
982.
Large‐scale migrations of brown bears in Eurasia and to North America during the Late Pleistocene
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Peeter Anijalg Simon Y. W. Ho John Davison Marju Keis Egle Tammeleht Katalina Bobowik Igor L. Tumanov Alexander P. Saveljev Elena A. Lyapunova Alexandr A. Vorobiev Nikolai I. Markov Alexey P. Kryukov Ilpo Kojola Jon E. Swenson Snorre B. Hagen Hans Geir Eiken Ladislav Paule Urmas Saarma 《Journal of Biogeography》2018,45(2):394-405
983.
984.
985.
W R Hagen M A Vanoni K Rosenbaum K D Schnackerz 《European journal of biochemistry》2000,267(12):3640-3646
Porcine liver dihydropyrimidine dehydrogenase is a homodimeric iron-sulfur flavoenzyme that catalyses the first and rate-limiting step of pyrimidine catabolism. The enzyme subunit contains 16 atoms each of nonheme iron and acid-labile sulfur, which are most likely arranged into four [4Fe-4S] clusters. However, the presence and role of such Fe-S clusters in dihydropyrimidine dehydrogenase is enigmatic, because they all appeared to be redox-inactive during absorbance-monitored titrations of the enzyme with its physiological substrates. In order to obtain evidence for the presence and properties of the postulated four [4Fe-4S] clusters of dihydropyrimidine dehydrogenase, a series of EPR-monitored redox titrations of the enzyme under a variety of conditions was carried out. No EPR-active species was present in the enzyme 'as isolated'. In full agreement with absorbance-monitored experiments, only a small amount of neutral flavin radical was detected when the enzyme was incubated with excess NADPH or dihydrouracil under anaerobic conditions. Reductive titrations of dihydropyrimidine dehydrogenase with dithionite at pH 9.5 and photochemical reduction at pH 7.5 and 9.5 in the presence of deazaflavin and EDTA led to the conclusion that the enzyme contains two [4Fe-4S]2+,1+ clusters, which both exhibit a midpoint potential of approximately -0.44 V (pH 9.5). The two clusters are most likely close in space, as demonstrated by the EPR signals which are consistent with dipolar interaction of two S = 1/2 species including a half-field signal around g approximately 3.9. Under no circumstances could the other two postulated Fe-S centres be detected by EPR spectroscopy. It is concluded that dihydropyrimidine dehydrogenase contains two [4Fe-4S] clusters, presumably determined by the C-terminal eight-iron ferredoxin-like module of the protein, whose participation in the enzyme-catalysed redox reaction is unlikely in light of the low midpoint potential measured. The presence of two additional [4Fe-4S] clusters in dihydropyrimidine dehydrogenase is proposed based on thorough chemical analyses on various batches of the enzyme and sequence analyses. The N-terminal region of dihydropyrimidine dehydrogenase is similar to the glutamate synthase beta subunit, which has been proposed to contain most, if not all, the cysteinyl ligands that participate in the formation of the [4Fe-4S] clusters of the glutamate synthase holoenzyme. It is proposed that the motif formed by the Cys residues at the N-terminus of the glutamate synthase beta subunit, which are conserved in dihydropyrimidine dehydrogenase and in several beta-subunit-like proteins or protein domains, corresponds to a novel fingerprint that allows the formation of [4Fe-4S] clusters of low to very low midpoint potential. 相似文献
986.
987.
Avery A. Lane Michelle K. McGuire Mark A. McGuire Janet E. Williams Kimberly A. Lackey Edward H. Hagen Abhishek Kaul Debela Gindola Dubale Gebeyehu Katherine E. Flores James A. Foster Daniel W. Sellen Elizabeth W. Kamau-Mbuthia Egidioh W. Kamundia Samwel Mbugua Sophie E. Moore Andrew M. Prentice Linda J. Kvist Gloria E. Otoo Juan M. Rodríguez Lorena Ruiz Rossina G. Pareja Lars Bode William J. Price Courtney L. Meehan 《American journal of physical anthropology》2019,169(3):526-539
988.
Navarro-Muñoz Jorge C. de Jong Auke W. Gerrits van den Ende Bert Haas Pieter-Jan Then Euníce R. Mohd Tap Ratna Collemare Jérôme Hagen Ferry 《Mycopathologia》2019,184(6):731-734
Mycopathologia - Candida vulturna is a new member of the Candida haemulonii species complex that recently received much attention as it includes the emerging multidrug-resistant pathogen Candida... 相似文献
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Huber G Heynen S Imsand C vom Hagen F Muehlfriedel R Tanimoto N Feng Y Hammes HP Grimm C Peichl L Seeliger MW Beck SC 《PloS one》2010,5(10):e13403