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

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

Author(s):  
Jiaxi Liu ◽  

The prediction of protein three-dimensional structure from amino acid sequence has been a challenge problem in bioinformatics, owing to the many potential applications for robust protein structure prediction methods. Protein structure prediction is essential to bioscience, and its research results are important for other research areas. Methods for the prediction an才d design of protein structures have advanced dramatically. The prediction of protein structure based on average hydrophobic values is discussed and an improved genetic algorithm is proposed to solve the optimization problem of hydrophobic protein structure prediction. An adjustment operator is designed with the average hydrophobic value to prevent the overlapping of amino acid positions. Finally, some numerical experiments are conducted to verify the feasibility and effectiveness of the proposed algorithm by comparing with the traditional HNN algorithm.


2009 ◽  
Vol 78 (3) ◽  
pp. 898-906 ◽  
Author(s):  
Ganwu Li ◽  
Yaping Feng ◽  
Subhashinie Kariyawasam ◽  
Kelly A. Tivendale ◽  
Yvonne Wannemuehler ◽  
...  

ABSTRACT Autotransporters (AT) are widespread in Gram-negative bacteria, and many of them are involved in virulence. An open reading frame (APECO1_O1CoBM96) encoding a novel AT was located in the pathogenicity island of avian pathogenic Escherichia coli (APEC) O1's virulence plasmid, pAPEC-O1-ColBM. This 3.5-kb APEC autotransporter gene (aatA) is predicted to encode a 123.7-kDa protein with a 25-amino-acid signal peptide, an 857-amino-acid passenger domain, and a 284-amino-acid β domain. The three-dimensional structure of AatA was also predicted by the threading method using the I-TASSER online server and then was refined using four-body contact potentials. Molecular analysis of AatA revealed that it is translocated to the cell surface, where it elicits antibody production in infected chickens. Gene prevalence analysis indicated that aatA is strongly associated with E. coli from avian sources but not with E. coli isolated from human hosts. Also, AatA was shown to enhance adhesion of APEC to chicken embryo fibroblast cells and to contribute to APEC virulence.


Genetics ◽  
1995 ◽  
Vol 139 (1) ◽  
pp. 267-286 ◽  
Author(s):  
J D Fackenthal ◽  
J A Hutchens ◽  
F R Turner ◽  
E C Raff

Abstract We have determined the lesions in a number of mutant alleles of beta Tub85D, the gene that encodes the testis-specific beta 2-tubulin isoform in Drosophila melanogaster. Mutations responsible for different classes of functional phenotypes are distributed throughout the beta 2-tubulin molecule. There is a telling correlation between the degree of phylogenetic conservation of the altered residues and the number of different microtubule categories disrupted by the lesions. The majority of lesions occur at positions that are evolutionarily highly conserved in all beta-tubulins; these lesions disrupt general functions common to multiple classes of microtubules. However, a single allele B2t6 contains an amino acid substitution within an internal cluster of variable amino acids that has been identified as an isotype-defining domain in vertebrate beta-tubulins. Correspondingly, B2t6 disrupts only a subset of microtubule functions, resulting in misspecification of the morphology of the doublet microtubules of the sperm tail axoneme. We previously demonstrated that beta 3, a developmentally regulated Drosophila beta-tubulin isoform, confers the same restricted morphological phenotype in a dominant way when it is coexpressed in the testis with wild-type beta 2-tubulin. We show here by complementation analysis that beta 3 and the B2t6 product disrupt a common aspect of microtubule assembly. We therefore conclude that the amino acid sequence of the beta 2-tubulin internal variable region is required for generation of correct axoneme morphology but not for general microtubule functions. As we have previously reported, the beta 2-tubulin carboxy terminal isotype-defining domain is required for suprastructural organization of the axoneme. We demonstrate here that the beta 2 variant lacking the carboxy terminus and the B2t6 variant complement each other for mild-to-moderate meiotic defects but do not complement for proper axonemal morphology. Our results are consistent with the hypothesis drawn from comparisons of vertebrate beta-tubulins that the two isotype-defining domains interact in a three-dimensional structure in wild-type beta-tubulins. We propose that the integrity of this structure in the Drosophila testis beta 2-tubulin isoform is required for proper axoneme assembly but not necessarily for general microtubule functions. On the basis of our observations we present a model for regulation of axoneme microtubule morphology as a function of tubulin assembly kinetics.


RNA ◽  
2012 ◽  
Vol 18 (4) ◽  
pp. 610-625 ◽  
Author(s):  
J. A. Cruz ◽  
M.-F. Blanchet ◽  
M. Boniecki ◽  
J. M. Bujnicki ◽  
S.-J. Chen ◽  
...  

1981 ◽  
Vol 195 (1) ◽  
pp. 31-40 ◽  
Author(s):  
F E Cohen ◽  
J Novotný ◽  
M J E Sternberg ◽  
D G Campbell ◽  
A F Williams

The Thy-1 membrane glycoprotein from rat brain is shown to have structural and sequence homologies with immunoglobulin (Ig) domains on the basis of the following evidence. 1. The two disulphide bonds of Thy-1 are both consistent with the Ig-fold. 2. The molecule contains extensive beta-structure as shown by the c.d. spectrum. 3. Secondary structure prediction locates beta-strands along the sequence in a manner consistent with the Ig-fold. 4. On the basis of rules derived from known beta-sheet structures, a three-dimensional structure with the Ig-fold is predicted as favourable for Thy-1. 5. Sequences in the proposed beta-strands of Thy-1 and known beta-strands of Ig domains show significant sequence homology. This homology is statistically more significant than for the comparison of proposed beta-strand sequences of beta 2-microglobulin with Ig domains. An hypothesis is presented for the possible functional significance of an evolutionary relationship between Thy-1 and Ig. It is suggested that both Thy-1 and Ig evolved from primitive molecules, with an Ig fold, which mediated cell--cell interactions. The present-day role of Thy-1 may be similar to that of the primitive domain.


2019 ◽  
Author(s):  
Kai Shimagaki ◽  
Martin Weigt

Statistical models for families of evolutionary related proteins have recently gained interest: in particular pairwise Potts models, as those inferred by the Direct-Coupling Analysis, have been able to extract information about the three-dimensional structure of folded proteins, and about the effect of amino-acid substitutions in proteins. These models are typically requested to reproduce the one- and two-point statistics of the amino-acid usage in a protein family, i.e. to capture the so-called residue conservation and covariation statistics of proteins of common evolutionary origin. Pairwise Potts models are the maximum-entropy models achieving this. While being successful, these models depend on huge numbers of ad hoc introduced parameters, which have to be estimated from finite amount of data and whose biophysical interpretation remains unclear. Here we propose an approach to parameter reduction, which is based on selecting collective sequence motifs. It naturally leads to the formulation of statistical sequence models in terms of Hopfield-Potts models. These models can be accurately inferred using a mapping to restricted Boltzmann machines and persistent contrastive divergence. We show that, when applied to protein data, even 20-40 patterns are sufficient to obtain statistically close-to-generative models. The Hopfield patterns form interpretable sequence motifs and may be used to clusterize amino-acid sequences into functional sub-families. However, the distributed collective nature of these motifs intrinsically limits the ability of Hopfield-Potts models in predicting contact maps, showing the necessity of developing models going beyond the Hopfield-Potts models discussed here.


Sign in / Sign up

Export Citation Format

Share Document