scholarly journals Structural role of the tyrosine residues of cytochrome c

1982 ◽  
Vol 205 (1) ◽  
pp. 153-165 ◽  
Author(s):  
C G Eley ◽  
G R Moore ◽  
R J Williams ◽  
W Neupert ◽  
P J Boon ◽  
...  

The tertiary structures of horse, tuna, Neurospora crassa, horse [Hse65,Leu67]- and horse [Hse65,Leu74]-cytochromes c were studied with high-resolution 1H n.m.r. spectroscopy. The amino acid sequences of these proteins differ at position 46, which is occupied by phenylalanine in the horse proteins but by tyrosine in the remaining two, and at positions 67, 74 and 97, which are all occupied by tyrosine residues in horse and tuna cytochrome c but in the other proteins are substituted by phenylalanine or leucine, though there is only one such substitution per protein. The various aromatic-amino-acid substitutions do not seriously affect the protein structure.

1964 ◽  
Vol 42 (6) ◽  
pp. 745-753 ◽  
Author(s):  
E. Margoliash

A comparison of the amino acid sequences of the cytochromes c from horse, pig, rabbit, chicken, and man leads to the conclusion that all have derived phylogenetically from a common primordial cytochrome c. The significance of the constant and of the variable features of these sequences with regard, on the one hand, to the structural aspects of the functional activities of the protein, and on the other, to the evolutionary relations between the various cytochromes c is discussed.


1973 ◽  
Vol 131 (3) ◽  
pp. 485-498 ◽  
Author(s):  
R. P. Ambler ◽  
Margaret Wynn

The amino acid sequences of the cytochromes c-551 from three species of Pseudomonas have been determined. Each resembles the protein from Pseudomonas strain P6009 (now known to be Pseudomonas aeruginosa, not Pseudomonas fluorescens) in containing 82 amino acids in a single peptide chain, with a haem group covalently attached to cysteine residues 12 and 15. In all four sequences 43 residues are identical. Although by bacteriological criteria the organisms are closely related, the differences between pairs of sequences range from 22% to 39%. These values should be compared with the differences in the sequence of mitochondrial cytochrome c between mammals and amphibians (about 18%) or between mammals and insects (about 33%). Detailed evidence for the amino acid sequences of the proteins has been deposited as Supplementary Publication SUP 50015 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1973), 131, 5.


1971 ◽  
Vol 124 (4) ◽  
pp. 783-785 ◽  
Author(s):  
E. W. Thompson ◽  
M. Richardson ◽  
D. Boulter

The amino acid sequences of buckwheat and cauliflower cytochromes c were determined on 1½μmol and 1μmol of protein respectively. The molecules consist of 111 residues and are homologous with other plant mitochondrial cytochromes c. Experimental details are given in a supplementary paper that has been deposited as Supplementary Publication SUP 50005 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1971), 121, 7.


1973 ◽  
Vol 133 (2) ◽  
pp. 251-254 ◽  
Author(s):  
R. H. Brown ◽  
D. Boulter

The amino acid sequence of cytochrome c from Nigella damascena L. was determined on 0.2μmol of protein. Peptides from a single chymotryptic digest were analysed by the dansyl–Edman procedure. These peptides were ordered by reference to the sequences of other plant cytochromes c, assuming that the Nigella cytochrome is homologous with the other cytochromes. Many of the Nigella peptides were one or two residues short when compared with the corresponding chymotryptic peptides from other plant cytochromes c. These residues are assumed to have been removed by an endogenous carboxypeptidase, and the identification and placing of these residues is entirely based on homology. These residues are numbered 3, 18, 42, 43, 44, 54, 67, 72, 73, 82 and 105. A number of other positions are almost entirely placed by homology. These are positions which could not be placed definitely by dansyl–Edman analysis or by dansylation after digestion with carboxypeptidase A, and are numbered 14, 15, 16, 39, 40, 85, 86, 87 and 88. Except for residue 15, all residues based entirely, or nearly so, on homology have been previously found invariant in sequences of plant cytochromes c. Experimental details are given in a supplementary paper that has been deposited as Supplementary Publication SUP 50017, at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1973) 131, 5.


1971 ◽  
Vol 124 (4) ◽  
pp. 787-791 ◽  
Author(s):  
E. W. Thompson ◽  
B. A. Notton ◽  
M. Richardson ◽  
D. Boulter

The amino acid sequences of Abutilon and Gossypium cytochromes c were determined on 1μmol of protein. The molecules consist of 111 residues and are homologous with other mitochondrial plant cytochromes c. Experimental details are given in a supplementary paper that has been deposited as Supplementary Publication SUP 50005 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1971), 121, 7.


1972 ◽  
Vol 128 (4) ◽  
pp. 971-974 ◽  
Author(s):  
R. H. Brown ◽  
M. Richardson ◽  
D. Boulter ◽  
J. A. M. Ramshaw ◽  
R. P. S. Jefferies

The amino acid sequence of a snail cytochrome c has been determined. The molecule consists of a single polypeptide chain of 104 residues, and is homologous with other mitochondrial cytochromes c. Unlike the cytochromes c from vertebrates, there is no acetyl blocking group at the N-terminus. A change in an otherwise invariant position has been observed in position 87. Comparison with amino acid sequences of cytochromes c from other sources indicates that the point of divergence of the molluscs and the vertebrates in evolutionary time was 720 million years ago. Experimental details are given in a supplementary paper that has been deposited as Supplementary Publication SUP 50009 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1972), 126, 5.


1987 ◽  
Vol 248 (2) ◽  
pp. 365-371 ◽  
Author(s):  
R P Ambler ◽  
M Daniel ◽  
L McLellan ◽  
T E Meyer ◽  
M A Cusanovich ◽  
...  

The amino acid sequences of the cytochromes c-554(548) and c' from the moderately halophilic bacterium Paracoccus sp., I.A.M. 203 (= A.T.C.C. 12084, N.C.I.B. 8669) have been determined. Cytochrome c-554(548) consists of a single polypeptide chain of 83 residues, and dimerizes strongly. The most similar protein of known sequence is the N-terminal half of the dihaem cytochrome c4, and other related proteins include the cytochrome c-554(547) of Thiobacillus neapolitanus and the cytochrome c-553 of Desulfovibrio vulgaris. Cytochrome c', which has a single polypeptide chain of 132 residues, is similar in sequence to cytochromes c' from phototrophic and denitrifying bacteria, but only shows about 36% sequence identity to the most similar protein of known sequence. Both of the Paracoccus proteins have a considerable excess of acidic amino acid side chains over basic ones, and a higher proportion of their basic amino acids is arginine than is usual in cytochromes c. Both these characteristics seem to be adaptations to increase the stability of the proteins in an environment of high ionic strength. Detailed evidence for the amino acid sequences of the proteins has been deposited as Supplementary Publication 50140 (24 pp.) at the British Library (Lending Division), Boston Spa, Yorkshire LS23 7BQ, U.K. from which copies are available on prepayment.


1974 ◽  
Vol 137 (1) ◽  
pp. 93-100 ◽  
Author(s):  
Richard H. Brown ◽  
Donald Boulter

Proposed amino acid sequences of cytochrome c from nasturtium (Tropaeolum majus L.), box-elder (Acer negundo L.), elder (Sambucus nigra L.) and parsnip (Pastinaca sativa L.) are presented. Because of the very limited amounts of cytochrome available from some plant sources, peptides derived from the cytochromes c have been sequenced by the semi-quantitative dansyl–Edman technique (Gray & Hartley, 1963) without supporting quantitative amino acid analyses. Because of the qualitative nature of the work, the sequences proposed must be regarded as tentative. Considerations of homology, although useful as a guide, have been kept to a minimum in the construction of sequences. Only the nasturtium sequence relies on considerations of homology for a complete ordering of the peptides. Where material permitted, each residue of a proposed sequence was determined at least once from both a tryptic and a chymotryptic peptide.


1991 ◽  
Vol 56 (4) ◽  
pp. 923-932
Author(s):  
Jana Stejskalová ◽  
Pavel Stopka ◽  
Zdeněk Pavlíček

The ESR spectra of peroxidase systems of methaemoglobin-ascorbic acid-hydrogen peroxide and methaemoglobin-haptoglobin complex-ascorbic acid-hydrogen peroxide have been measured in the acetate buffer of pH 4.5. For the system with methaemoglobin an asymmetrical signal with g ~ 2 has been observed which is interpreted as the perpendicular region of anisotropic spectrum of superoxide radical. On the other hand, for the system with methaemoglobin-haptoglobin complex the observed signal with g ~ 2 is symmetrical and is interpreted as a signal of delocalized electron. After realization of three repeatedly induced peroxidase processes the ESR signal of the perpendicular part of anisotropic spectrum of superoxide radical is distinctly diminished, whereas the signal of delocalized electron remains practically unchanged. An amino acid analysis of methaemoglobin along with results of the ESR measurements make it possible to derive a hypothesis about the role of haptoglobin in increasing of the peroxidase activity of methaemoglobin.


2021 ◽  
Vol 22 (3) ◽  
pp. 1018
Author(s):  
Hiroaki Yokota

Helicases are nucleic acid-unwinding enzymes that are involved in the maintenance of genome integrity. Several parts of the amino acid sequences of helicases are very similar, and these quite well-conserved amino acid sequences are termed “helicase motifs”. Previous studies by X-ray crystallography and single-molecule measurements have suggested a common underlying mechanism for their function. These studies indicate the role of the helicase motifs in unwinding nucleic acids. In contrast, the sequence and length of the C-terminal amino acids of helicases are highly variable. In this paper, I review past and recent studies that proposed helicase mechanisms and studies that investigated the roles of the C-terminal amino acids on helicase and dimerization activities, primarily on the non-hexermeric Escherichia coli (E. coli) UvrD helicase. Then, I center on my recent study of single-molecule direct visualization of a UvrD mutant lacking the C-terminal 40 amino acids (UvrDΔ40C) used in studies proposing the monomer helicase model. The study demonstrated that multiple UvrDΔ40C molecules jointly participated in DNA unwinding, presumably by forming an oligomer. Thus, the single-molecule observation addressed how the C-terminal amino acids affect the number of helicases bound to DNA, oligomerization, and unwinding activity, which can be applied to other helicases.


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