Influence of oxygen on the synthesis of flavocytochrome b2 by the yeast Hansenula anomala

1982 ◽  
Vol 16 (4) ◽  
pp. 171-173
Author(s):  
M. C. Hours
Keyword(s):  
Flavocytochrome B2 ◽  
Hansenula Anomala

Comparison of the Amino Acid Sequence of L–Mandelate Dehydrogenase From Rhodotorula Graminis With Other L–2–Hydroxyacid Dehydrogenase Enzyme and its Primary Structure Prediction

2012 ◽  
Author(s):  
Rosli Md. Illias ◽  
Graeme A. Reid ◽  
Nadzarah A. Wahab
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Lactate Dehydrogenase ◽  
Primary Structure ◽  
Structure Prediction ◽  
Three Dimensional ◽  
Glycolate Oxidase ◽  
Dimensional Structure ◽  
Flavocytochrome B2 ◽  
Hansenula Anomala

Perbandingan struktur primer L(+)–mendalate dehydrogenase (L–MDH) daripada yis Rhodotorula graminis dengan protein lain di dalam bank data protein menunjukkan persamaan di antara protein ini dengan kumpulan enzim L–2–hidroksiasid dehidrogenase. LMDH daripada R. graminis mempamerkan kesamaan antara 26–42% kepada L–lactate dehidrogenase daripada Sacchomoryces cerevisiae, L–lactate dehidrogenase daripada Hansenula anomala, glikolat oksida daripada bayam, L–laktat dehidrogenase daripada Escherichia coli, LMDH daripada Psedomonas putida dan laktat–2 monooksigenase daripada Mycobakterium smegmatis. Asid amino yang penting secara strukturnya bagi LMDH diramalkan secara perbandingan dengan bahagian penting domain sitokram dan domain perlekatan FMN yang diperoleh daripada struktur tiga dimensi L–laktat dehidrogenase daripada Sacchoromyces cerevisiae. Kata kunci: L-MDH; Rhodotorula gramisis; L(+)-mandalate dehydrogenase; asid amino,flavocytochrome b2 A comparison of the primary structure or L–mandelate dehydrogenase (L–MDH) from Rhodotorula graminis with other proteins from the protein databank suggests that there is similarity between this protein and L–2–hydroxyacid dehydrogenase enzymes. R graminis LMDH exhibits 26–42% identity to L–lactate dehydrogenase from Saccharomyces cerevisiae, L–lactate dehydrogenase from Hansenula anomala, glycolate oxidase from spinach, L–lactate dehydrogenase from Escherichia coli, L–mandelate dehydrogenase from Pseudomonas putida and lactate–2–monooxygenase from Mycobacterium smegmatis. Structurally conserved amino acids are predicted from LMDH sequences corresponding to important regions of the cytochrome and FMN–binding domain defined from the known three–dimensional structure of the L–lactate dehyrogenase from Sacchoromyces cerevisiae. Key words: L-MDH; Rhodotorula graminis; L-mandelate dehydrogenase; amino acid;flavocytochrome b2

scholarly journals Amino-acid sequence of the cytochrome-b5-like heme-binding domain from Hansenula anomala flavocytochrome b2

1987 ◽  
Vol 169 (3) ◽  
pp. 539-544 ◽  
Author(s):  
Pierre-Yves HAUMONT ◽  
Marie-Antoinette THOMAS ◽  
Francoise LABEYRIE ◽  
Florence LEDERER
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Cytochrome B5 ◽  
Binding Domain ◽  
Heme Binding ◽  
Flavocytochrome B2 ◽  
Hansenula Anomala

scholarly journals Structural basis for the kinetic differences between flavocytochromes b2 from the yeasts Hansenula anomala and Saccharomyces cerevisiae

1989 ◽  
Vol 263 (3) ◽  
pp. 973-976 ◽  
Author(s):  
M T Black ◽  
F J Gunn ◽  
S K Chapman ◽  
G A Reid
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Amino Acid Sequences ◽  
Structural Basis ◽  
Gene Encoding ◽  
Net Charge ◽  
Flavocytochrome B2 ◽  
Sequence Identity ◽  
Hansenula Anomala ◽  
Catalytic Behaviour ◽  
Surface Loops

To understand the structural basis for the different catalytic behaviour of the flavocytochromes b2 from Saccharomyces cerevisiae and Hansenula anomala we have cloned and sequenced the gene encoding the latter. We have compared the amino acid sequences of the mature proteins in the context of the known crystal structure of S. cerevisiae flavocytochrome b2. Overall there is 60% sequence identity, but two surface loops in particular are strikingly different in primary structure and net charge.

scholarly journals A temperature-jump study of the electron transfer reactions in Hansenula anomala flavocytochrome b2

1984 ◽  
Vol 140 (1) ◽  
pp. 39-45 ◽  
Author(s):  
Mariella TEGONI ◽  
Maria Chiara SILVESTRINI ◽  
Francoise LABEYRIE ◽  
Maurizio BRUNORI
Keyword(s):  
Electron Transfer ◽  
Temperature Jump ◽  
Transfer Reactions ◽  
Electron Transfer Reactions ◽  
Flavocytochrome B2 ◽  
Hansenula Anomala

scholarly journals Electron-transfer steps involved in the reactivity of Hansenula anomala flavocytochrome b2 as deduced from deuterium isotope effects and simulation studies

1991 ◽  
Vol 274 (1) ◽  
pp. 207-217 ◽  
Author(s):  
C Capeillère-Blandin
Keyword(s):  
Electron Transfer ◽  
Steady State ◽  
Phase I ◽  
Rate Constants ◽  
Intramolecular Electron Transfer ◽  
Simulation Studies ◽  
First Order ◽  
Flavocytochrome B2 ◽  
Hansenula Anomala ◽  
Phase Phase

The L-lactate-flavocytochrome b2-ferricyanide electron-transfer system from the yeast Hansenula anomala was investigated by rapid-reaction techniques. The kinetics of reduction of oxidized flavocytochrome b2 by L-lactate and L-[2H]lactate were biphasic both for flavin and haem prosthetic groups and at all concentrations tested. The first-order rate constants of the rapid and slow phases depended upon substrate concentrations, a saturation behaviour being exhibited. Substitution of the C alpha-H atom by 2H was found to cause appreciable changes in the rate constants for the initial reduction of flavin and haem (phase I), which were respectively about 3-fold and 2-fold less than with L-lactate. In contrast, no significant isotope effect was noted on the apparent reduction rate constants of the slow phase, phase II. Under steady-state conditions an isotope effect of 2.0 was found on the overall electron transfer from L-lactate to ferricyanide. These transient reduction results were discussed in terms of a kinetic model implying intra- and inter-protomer electron exchanges between flavin and haem b2, all of which have been experimentally described. Computer simulations indicate that the reaction scheme provides a reasonable explanation of the fast-reduction phase, phase I (in absence of acceptor). The pseudo-first-order rate constant for oxidation of reduced haem b2 in flavocytochrome b2 increased with increasing ferricyanide concentration in a hyperbolic fashion. The limiting value at infinite ferricyanide concentration, which was attributed to the intramolecular electron-transfer rate from ferroflavocytochrome b2 to the iron of ferricyanide within a complex, was 920 +/- 50 s-1 at pH 7.0 and 5 degrees C. Stopped-flow and rapid-freezing measurements showed haem b2 and flavin to be 90 and 44% oxidized respectively under steady-state conditions in presence of ferricyanide. Simulation studies were carried out to check the participation of the proposed reduction sequence in the overall catalytic reaction together with the role of reduced haem b2 (Hr) and flavin semiquinone (Fsq) as electron donors to ferricyanide. When the rate of the intramolecular electron-transfer exchange between Fsq and ferricyanide was adjusted to 200 s-1, simulated data accounted for molar activities defined under various conditions of L-lactate, [2H]lactate and ferricyanide concentrations. Simulation studies were extended to data obtained using cytochrome c as acceptor and reaction catalysed by Saccharomyces cerevisiae flavocytochrome b2. The differences in reactivity observed for Hr and Fsq with ferricyanide and cytochrome c were discussed in terms of redox potentials, electrostatic interactions, distances and accessibility of the participating groups.

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