Primary structure Protein sequencing

The primary structure - the sequence of peptide-bonded amino acids in the protein chain and the location of any disulfide bridges. 

The final method of RNA structure prediction, empirical algorithms, are also analogous to primary-structure motif detection methods. Known RNA structural motifs are extracted from structural databases, and the primary-structure patterns underlying these motifs are identified. Novel RNA sequences are then scanned for these primary-structure motifs much like a novel protein sequence might be scanned for CDs. In essence, these methods search the primary structure of sequences for conserved motifs that indicate secondary structure. One of the most flexible and powerful empirical tools is RNAMotif, which is freely available for download, but does not have an associated web-server (23). 

Primary structure The sequence of the monomeric units in proteins, carbohydrates, and so on. 

A protein or a polypeptide is composed of amino acids linked together by peptide bonds, with amino acids as the monomeric units of the polypeptide. The order of amino acids in a protein is known as the primary structure of that protein. The specific sequence of amino acids in the protein determines its three-dimensional structure and ultimately its function. The amino acids are numbered sequentially, beginning at the amino terminus of the polypeptide. For example, the 45th amino acid in the sequence would be identified as residue 45. Most often, scientists refer to an individual residue using both the name of the amino acid and its position. Therefore, if residue 45 in a particular polypeptide sequence is serine, that residue would be referred to as serine-45, see also Peptide Bond Primary Structure Proteins. 

Cyanogen bromide (BrC=N) causes the hydrolysis of the amide bond on the C-side of a methionine residue. Cyanogen bromide is more specific than the endopeptidases about what peptide bonds it cleaves, so it provides more reliable information about the primary structure (the sequence of amino acids). Because cyanogen bromide is not a protein and therefore does not recognize the substrate by its shape, cyanogen bromide will still cleave the peptide bond if proline is at the cleavage site. 

Primary structure the sequence of amino acids in the polypeptide chain (see Figure 1.3). This is unique to each protein, and is determined (primarily) by the genetic information encoded in the DNA of the relevant gene. 

Primary structure The sequence of amino acids in a peptide or protein. 

Thoma, R., G. Holleschak, R. Hileman, etal. 2001. Primary Structural Protein Characterization of Corn Event MON 863 Cry3Bbl.l 1098 Protein Using N-Terminal Sequencing and MALDI Time of Flight Mass Spectrometric Techniques Lab Proj No. 17154 MSL-17154. Unpubl. study prepared by Monsanto Co. 21 p. 

The primary structure of a peptide is given by its ammo acid sequence plus any disulfide bonds between two cysteine residues The primary structure is determined by a systematic approach m which the protein is cleaved to smaller fragments even individual ammo acids The smaller fragments are sequenced and the mam sequence deduced by finding regions of overlap among the smaller peptides... 

By analogy to the levels of structure of proteins the primary structure of DNA IS the sequence of bases along the polynucleotide chain and the A DNA B DNA and Z DNA helices are varieties of secondary structures... 

Primary carbon (Section 2 13) A carbon that is directly at tached to only one other carbon Primary structure (Section 27 8) The sequence of ammo acids in a peptide or protein... 

Figure 1.1 The amino acid sequence of a protein s polypeptide chain is called Its primary structure. Different regions of the sequence form local regular secondary structures, such as alpha (a) helices or beta (P) strands. The tertiary structure is formed by packing such structural elements into one or several compact globular units called domains. The final protein may contain several polypeptide chains arranged in a quaternary structure. By formation of such tertiary and quaternary structure amino acids far apart In the sequence are brought close together in three dimensions to form a functional region, an active site.

Domains are formed by different combinations of secondary structure elements and motifs. The a helices and p strands of the motifs are adjacent to each other in the three-dimensional structure and connected by loop regions. Sequentially adjacent motifs, or motifs that are formed from consecutive regions of the primary structure of a polypeptide chain, are usually close together in the three-dimensional structure (Figure 2.20). Thus to a first approximation a polypeptide chain can be considered as a sequential arrangement of these simple motifs. The number of such combinations found in proteins is limited, and some combinations seem to be structurally favored. Thus similar domain structures frequently occur in different proteins with different functions and with completely different amino acid sequences. 

Different techniques give different and complementary information about protein structure. The primary structure is obtained by biochemical methods, either by direct determination of the amino acid sequence from the protein or indirectly, but more rapidly, from the nucleotide sequence of the... 

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