scholarly journals Biophysics : Aspects of Amino Acids Sequence in Proteins and Nucleotide Sequence in Nucleic Acids

2013 ◽  
Vol 4 ◽  
pp. 65-74
Author(s):  
Khadka Bahadur Chhetri

Protein is the polypeptide chain of amino-acid sequence. Proteins of all species, from bacteria to humans, are made up from the same set of 20 standard amino acids. In order to carry out their function they must take a particular shape which is known as fold. All the enzymes hormones and antibodies are also proteins. To treat certain toxic-microorganism or invader we need certain antigen-antibody complex in the organisms. Just as amino-acid sequence forms the proteins, the polynucleotide sequence forms the nucleic acids. The gene is a part of DNA macromolecule responsible for the synthesis of protein chains. There are 20 amino-acids responsible for the formation of protein and 4 nucleotides responsible for the formation of DNA (RNA). Therefore, we can say that protein text is written in 20-letter and the DNA (RNA) text is written in 4-letter language. The information contained in genes in DNA is transferred to mRNA during transcription.The Himalayan Physics Vol. 4, No. 4, 2013 Page: 65-74 Uploaded date: 12/23/2013 

1986 ◽  
Vol 235 (3) ◽  
pp. 895-898 ◽  
Author(s):  
M S López de Haro ◽  
A Nieto

An almost full-length cDNA coding for pre-uteroglobin from hare lung was cloned and sequenced. The derived amino acid sequence indicated that hare pre-uteroglobin contained 91 amino acids, including a signal peptide of 21 residues. Comparison of the nucleotide sequence of hare pre-uteroglobin cDNA with that previously reported for the rabbit gene indicated five silent point substitutions and six others leading to amino acid changes in the coding region. The untranslated regions of both pre-uteroglobin mRNAs were very similar. The amino acid changes observed are discussed in relation to the different progesterone-binding abilities of both homologous proteins.


1998 ◽  
Vol 42 (5) ◽  
pp. 1245-1248 ◽  
Author(s):  
François Sanschagrin ◽  
Julien Dufresne ◽  
Roger C. Levesque

ABSTRACT We have determined the nucleotide sequence of the blaSgene encoding the carbapenem-hydrolyzing L-1 β-lactamase fromStenotrophomonas maltophilia GN12873. Analysis of the DNA and deduced amino acid sequences identified a product of 290 amino acids. Comparisons of the L-1 amino acid sequence with those of other zinc β-lactamases showed 88.6% identity with the L-1 enzyme fromS. maltophilia IID1275 and less than 20% identity with other class B metalloenzymes.


1986 ◽  
Vol 238 (2) ◽  
pp. 475-483 ◽  
Author(s):  
K Duncan ◽  
S Chaudhuri ◽  
M S Campbell ◽  
J R Coggins

The enzyme 3-dehydroquinase was purified in milligram quantities from an overproducing strain of Escherichia coli. The amino acid sequence was deduced from the nucleotide sequence of the aroD gene and confirmed by determining the amino acid composition of the overproduced enzyme and its N-terminal amino acid sequence. The complete polypeptide chain consists of 240 amino acid residues and has a calculated subunit Mr of 26,377. Transcript mapping revealed that aroD is a typical monocistronic gene.


1986 ◽  
Vol 235 (3) ◽  
pp. 769-773 ◽  
Author(s):  
J R Vanfleteren ◽  
S M Van Bun ◽  
L L Delcambe ◽  
J J Van Beeumen

The complete amino acid sequence of histone H2B from the nematode Caenorhabditis elegans was determined. The protein as obtained by us is a mixture of multiple forms. Approx. 90% of the molecules consist of a polypeptide chain of 122 amino acids with alanine as N-terminal residue and proline at the second position. In the remaining 10% alanine is lacking and the chain starts with proline. In addition to the heterogeneity of chain length, polymorphism occurs at the positions 7 (Ala/Lys), 14 (Ala/Lys) and 72 (Ala/Ser) of the major chain and at position 6 (Ala/Lys) of the shorter chain. In the N-terminal third of the molecule there is a high degree of sequence homology to the corresponding region in H2B from Drosophila (insect), Patella (mollusc) and Asterias (starfish). In contrast, this part of the molecule differs considerably from mammalian histone H2B.


1967 ◽  
Vol 167 (1009) ◽  
pp. 331-347 ◽  

Genes are made of nucleic acid. Enzymes are made of protein. The amino acid sequence of a particular protein is synthesized under instruction from a particular piece of nucleic acid. Each protein is made of one or more polypeptide chains, synthesized by condensing together amino acids, head to tail, with the elimination of water. A typical polypeptide chain is several hundred amino acid residues long. Nevertheless only twenty different kinds of amino acids are commonly found in proteins. This standard set of twenty is the same throughout nature. Nucleic acid is made of polynucleotide chains. The repeating unit of the chain is a sugar (ribose for RNA , deoxyribose for DNA ) connected to a phosphate. A base is joined on to each sugar. There are four common bases in nucleic acid. DNA usually has adenine, guanine, cytosine and thymine. In RNA thymine is replaced by uracil.


1987 ◽  
Vol 65 (4) ◽  
pp. 338-344 ◽  
Author(s):  
James Michael Rini ◽  
Theo Hofmann ◽  
Jeremy P. Carver

The complete amino acid sequence of the alpha chains of both isolectins found in pea seeds has been determined using automated Edman degradation. We show that the alpha chains of these two proteins differ only at their C-termini: isolectin B is two amino acids longer than isolectin A. Furthermore, the alpha chains of both isolectins are shorter than would be predicted from the nucleotide sequence of a cDNA clone for pea lectin. We suggest, therefore, that these proteins arise from differential C-terminal processing. Amino acid composition data and C-terminal analysis show that the beta chains have also been processed at their C-termini, but in this case identical chains for both isolectins are produced.


1996 ◽  
Vol 40 (5) ◽  
pp. 1126-1133 ◽  
Author(s):  
H Oppegaard ◽  
H Sørum

The DNA gyrase gyrA gene from the fish pathogen Aeromonas salmonicida 2148/89 was cloned, and the nucleotide sequence was determined. An open reading frame of 2,766 nucleotides was identified and was found to encode a protein of 922 amino acids with a calculated molecular mass of 101.1 kDa. The derived amino acid sequence shared a high degree of identity with other DNA gyrase A proteins, in particular, with other gram-negative GyrA sequences. When the amino acid sequence of A. salmonicida GyrA was compared with that of Escherichia coli GyrA, a number of conserved residues were present at identical coordinates, including the catalytic Tyr residue at position 122 (Tyr-122) and residues whose substitution confers quinolone resistance, notably, Ser-83, Ala-67, Gly-81, Asp-87, Ala-84, and Gln-106. An intragenic region corresponding to 48 amino acids, which is not present in E. coli or other bacteria, was identified in the C-terminal part of A. salmonicida GyrA. This intragenic region shared sequence identity with various DNA-binding proteins of both prokaryotic and eukaryotic origins.


1974 ◽  
Vol 137 (1) ◽  
pp. 101-112 ◽  
Author(s):  
M. Richardson

The amino acid sequence of subunit A of the potato chymotryptic inhibitor I was determined. The sequence was deduced from analysis of fragments and peptides derived from the protein by cleavage with cyanogen bromide, N-bromosuccinimide and dilute acid, and by digestion with trypsin, thermolysin, pepsin and papain. The molecule consists of a single polypeptide chain of 84 residues, which contains two homologous regions each of 13 amino acids. The protein does not appear to be homologous with any other known proteinase inhibitors.


1979 ◽  
Vol 42 (05) ◽  
pp. 1652-1660 ◽  
Author(s):  
Francis J Morgan ◽  
Geoffrey S Begg ◽  
Colin N Chesterman

SummaryThe amino acid sequence of the subunit of human platelet factor 4 has been determined. Human platelet factor 4 consists of identical subunits containing 70 amino acids, each with a molecular weight of 7,756. The molecule contains no methionine, phenylalanine or tryptophan. The proposed amino acid sequence of PF4 is: Glu-Ala-Glu-Glu-Asp-Gly-Asp-Leu-Gln-Cys-Leu-Cys-Val-Lys-Thr-Thr-Ser- Gln-Val-Arg-Pro-Arg-His-Ile-Thr-Ser-Leu-Glu-Val-Ile-Lys-Ala-Gly-Pro-His-Cys-Pro-Thr-Ala-Gin- Leu-Ile-Ala-Thr-Leu-Lys-Asn-Gly-Arg-Lys-Ile-Cys-Leu-Asp-Leu-Gln-Ala-Pro-Leu-Tyr-Lys-Lys- Ile-Ile-Lys-Lys-Leu-Leu-Glu-Ser. From consideration of the homology with p-thromboglobulin, disulphide bonds between residues 10 and 36 and between residues 12 and 52 can be inferred.


2020 ◽  
Author(s):  
Michele Larocca

<p>Protein folding is strictly related to the determination of the backbone dihedral angles and depends on the information contained in the amino acid sequence as well as on the hydrophobic effect. To date, the type of information embedded in the amino acid sequence has not yet been revealed. The present study deals with these problematics and aims to furnish a possible explanation of the information contained in the amino acid sequence, showing and reporting rules to calculate the backbone dihedral angles φ. The study is based on the development of mechanical forces once specific chemical interactions are established among the side chain of the residues in a polypeptide chain. It aims to furnish a theoretical approach to predict backbone dihedral angles which, in the future, may be applied to computational developments focused on the prediction of polypeptide structures.</p>


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