Mutation of isoleucine 705 of the oxidosqualene-lanosterol cyclase from Saccharomyces cerevisiae affects lanosterol's C/D-ring cyclization and 17α/β-exocyclic side chain stereochemistry

2011 ◽  
Vol 9 (4) ◽  
pp. 1092-1097 ◽  
Author(s):  
Tung-Kung Wu ◽  
Yi-Chun Chang ◽  
Yuan-Ting Liu ◽  
Cheng-Hsiang Chang ◽  
Hao-Yu Wen ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Side Chain ◽  
Oxidosqualene Lanosterol Cyclase

Backbone and side-chain resonance assignments of centromeric protein Scm3 from Saccharomyces cerevisiae

2019 ◽  
Vol 13 (2) ◽  
pp. 267-273
Author(s):  
Anusri Bhattacharya ◽  
Vaibhav Kumar Shukla ◽  
Ramakrishna V. Hosur ◽  
Ashutosh Kumar
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Resonance Assignments ◽  
Side Chain ◽  
Chain Resonance ◽  
Centromeric Protein ◽  
Side Chain Resonance

scholarly journals The introduction of the C-22–C-23 ethylenic linkage in ergosterol biosynthesis

1968 ◽  
Vol 106 (3) ◽  
pp. 623-626 ◽  
Author(s):  
M Akhtar ◽  
M. A. Parvez ◽  
P. F. Hunt
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chemical Synthesis ◽  
Good Yield ◽  
The Other ◽  
Side Chain ◽  
Ergosterol Biosynthesis ◽  
Hydrogen Atoms ◽  
Whole Cells ◽  
C 23 ◽  
Methylene Derivative

Methods for the chemical synthesis of [23−3H2]lanosterol, [23,25−3H3]24-methyldihydrolanosterol and [24,28−3H2]24-methyldihydrolanosterol are described. It is shown that, in the biosynthesis of ergosterol from [26,27−14C2,23−3H2]lanosterol by the whole cells of Saccharomyces cerevisiae, one of the original C-23 hydrogen atoms is lost and the other is retained at C-23 of ergosterol. It is also shown that 24-methyldihydrolanosterol is converted into ergosterol in good yield and without prior conversion into a 24-methylene derivative. On the basis of these results possible pathways for the formation of the ergosterol side chain from a 24-methylene side chain are discussed.

Contribution of leucine 85 to the structure and function of Saccharomyces cerevisiae iso-1 cytochrome c

2001 ◽  
Vol 79 (4) ◽  
pp. 517-524 ◽  
Author(s):  
Jonathan C Parrish ◽  
J Guy Guillemette ◽  
Carmichael JA Wallace
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Electron Transfer ◽  
Electron Transport ◽  
Cytochrome C ◽  
Transport Processes ◽  
Complex Iii ◽  
Side Chain ◽  
Inner Mitochondrial Membrane ◽  
And Function ◽  
First Time

Cytochrome c is a small electron-transport protein whose major role is to transfer electrons between complex III (cytochrome reductase) and complex IV (cytochrome c oxidase) in the inner mitochondrial membrane of eukaryotes. Cytochrome c is used as a model for the examination of protein folding and structure and for the study of biological electron-transport processes. Amongst 96 cytochrome c sequences, residue 85 is generally conserved as either isoleucine or leucine. Spatially, the side chain is associated closely with that of the invariant residue Phe82, and this interaction may be important for optimal cytochrome c activity. The functional role of residue 85 has been examined using six site-directed mutants of Saccharomyces cerevisiae iso-1 cytochrome c, including, for the first time, kinetic data for electron transfer with the principle physiological partners. Results indicate two likely roles for the residue: first, heme crevice resistance to ligand exchange, sensitive to both the hydrophobicity and volume of the side chain; second, modulation of electron-transport activity through maintenance of the hydrophobic character of the protein in the vicinity of Phe82 and the exposed heme edge, and possibly of the ability of this region to facilitate redox-linked conformational change.Key words: protein engineering, cytochrome c, structure-function relations, electron transfer, hydrophobic packing.

The induced biosynthesis of 7-dehydrocholesterols in yeast: potential sources of new provitamin D3 analogs

1976 ◽  
Vol 54 (7) ◽  
pp. 657-665 ◽  
Author(s):  
L. Avruch ◽  
S. Fischer ◽  
H. Pierce Jr. ◽  
A. C. Oehlschlager
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Structural Analog ◽  
Side Chain ◽  
Low Concentrations ◽  
Potential Sources

The effect of low concentrations of a specifically designed sterol-24-transmethylase inhibitor, 25-aza-24,25-dihydrozymosterol (10) on sterol production in Saccharomyces cerevisiae was examined. The synthesis of cholesta-5,7,22,24-tetraen-3β-ol (4), its 7,22,24 analog (15) and the 7,24 analog (5) coupled with the availability of zymosterol (6) and cholesta-5,7,24-3β-ol (3) derivatives facilitated a search for these sterols in cultures treated with this inhibitor.When S. cerevisiae was grown in the presence of 1.3 and 5 μM10, it produced no ergosterol but accumulated zymosterol (6), cholesta-5,7,22, 24-tetraen-3β-ol (4) and related C27 sterols (3 and 5). These results indicate blockage of the side chain methylation that normally occurs during the biosynthesis of ergosterol in yeast by compound 10 is efficient. The cholesta-5,7,22,24-tetraen-3β-ol is a close structural analog of provitamin D3 (7-dehydrocholesterol). The inhibited yeast thus provides a source of a potentially new provitamin D3 substitute.

scholarly journals Biological significance of the side chain length of ubiquinone in Saccharomyces cerevisiae

FEBS Letters ◽  
1998 ◽  
Vol 431 (2) ◽  
pp. 241-244 ◽  
Author(s):  
Kazunori Okada ◽  
Tomohiro Kainou ◽  
Hideyuki Matsuda ◽  
Makoto Kawamukai
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Chain Length ◽  
Biological Significance ◽  
Side Chain ◽  
Side Chain Length

scholarly journals Eukaryotic Wobble Uridine Modifications Promote a Functionally Redundant Decoding System

2008 ◽  
Vol 28 (10) ◽  
pp. 3301-3312 ◽  
Author(s):  
Marcus J. O. Johansson ◽  
Anders Esberg ◽  
Bo Huang ◽  
Glenn R. Björk ◽  
Anders S. Byström
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Side Chain ◽  
Side Chains ◽  
Methyl Group ◽  
Wobble Position ◽  
Naturally Occurring

ABSTRACT The translational decoding properties of tRNAs are modulated by naturally occurring modifications of their nucleosides. Uridines located at the wobble position (nucleoside 34 [U34]) in eukaryotic cytoplasmic tRNAs often harbor a 5-methoxycarbonylmethyl (mcm5) or a 5-carbamoylmethyl (ncm5) side chain and sometimes an additional 2-thio (s2) or 2′-O-methyl group. Although a variety of models explaining the role of these modifications have been put forth, their in vivo functions have not been defined. In this study, we utilized recently characterized modification-deficient Saccharomyces cerevisiae cells to test the wobble rules in vivo. We show that mcm5 and ncm5 side chains promote decoding of G-ending codons and that concurrent mcm5 and s2 groups improve reading of both A- and G-ending codons. Moreover, the observation that the mcm5U34- and some ncm5U34-containing tRNAs efficiently read G-ending codons challenges the notion that eukaryotes do not use U-G wobbling.

scholarly journals Studies on the Biosynthesis of the ergosterol side chain

1969 ◽  
Vol 113 (4) ◽  
pp. 727-732 ◽  
Author(s):  
M Akhtar ◽  
M. A. Parvez ◽  
P. F. Hunt
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Good Yield ◽  
Yeast Cells ◽  
Side Chain ◽  
Convenient Synthesis

1. A convenient synthesis of 24-methylene[23,25−3H3]dihydrolanosterol is described. 2. A general anaerobic–aerobic method for the incorporation of sterols into whole yeast cells is also described and illustrated by experiments with 3H-labelled lanosterol. 3. The method was used to convert labelled 24-methylene-dihydrolanosterol into ergosterol, in good yield, by Saccharomyces cerevisiae. 4. Degradation of the biosynthetic ergosterol provided confirmation of the conversion, which supports the proposed mechanism for the biosynthesis of the ergosterol side chain. 5. Mechanisms for the further conversion of the 24-methylene side chain into the ergosterol side chain are discussed and it was shown that a compound, [3α−3H1]-ergost-7-en-3β-ol, with a fully saturated side chain, can also be efficiently incorporated into ergosterol. 6. This result was confirmed by a procedure involving formation of the 5,8-epidioxide and subsequently the 5,8-epidioxy-22,23-epoxide of the biosynthetic ergosterol.

The cysteine 703 to isoleucine or histidine mutation of the oxidosqualene-lanosterol cyclase from Saccharomyces cerevisiae generates an iridal-type triterpenoid

Biochimie ◽  
2012 ◽  
Vol 94 (11) ◽  
pp. 2376-2381 ◽  
Author(s):  
Cheng-Hsiang Chang ◽  
Yi-Chi Chen ◽  
Sheng-Wei Tseng ◽  
Yuan-Ting Liu ◽  
Hao-Yu Wen ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Oxidosqualene Lanosterol Cyclase
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