scholarly journals Amino-Acid Sequence of lac Repressor from Escherichia coli. Isolation, Sequence Analysis and Sequence Assembly of Tryptic Peptides and Cyanogen-Bromide Fragments

1975 ◽  
Vol 59 (2) ◽  
pp. 491-509 ◽  
Author(s):  
Konrad BEYREUTHER ◽  
Klaus ADLER ◽  
Ellen FANNING ◽  
Carolyn MURRAY ◽  
Norbert GEISLER ◽  
...  

2002 ◽  
Vol 184 (11) ◽  
pp. 2906-2913 ◽  
Author(s):  
Keietsu Abe ◽  
Fumito Ohnishi ◽  
Kyoko Yagi ◽  
Tasuku Nakajima ◽  
Takeshi Higuchi ◽  
...  

ABSTRACT Tetragenococcus halophila D10 catalyzes the decarboxylation of l-aspartate with nearly stoichiometric release of l-alanine and CO2. This trait is encoded on a 25-kb plasmid, pD1. We found in this plasmid a putative asp operon consisting of two genes, which we designated aspD and aspT, encoding an l-aspartate-β-decarboxylase (AspD) and an aspartate-alanine antiporter (AspT), respectively, and determined the nucleotide sequences. The sequence analysis revealed that the genes of the asp operon in pD1 were in the following order: promoter → aspD → aspT. The deduced amino acid sequence of AspD showed similarity to the sequences of two known l-aspartate-β-decarboxylases from Pseudomonas dacunhae and Alcaligenes faecalis. Hydropathy analyses suggested that the aspT gene product encodes a hydrophobic protein with multiple membrane-spanning regions. The operon was subcloned into the Escherichia coli expression vector pTrc99A, and the two genes were cotranscribed in the resulting plasmid, pTrcAsp. Expression of the asp operon in E. coli coincided with appearance of the capacity to catalyze the decarboxylation of aspartate to alanine. Histidine-tagged AspD (AspDHis) was also expressed in E. coli and purified from cell extracts. The purified AspDHis clearly exhibited activity of l-aspartate-β-decarboxylase. Recombinant AspT was solubilized from E. coli membranes and reconstituted in proteoliposomes. The reconstituted AspT catalyzed self-exchange of aspartate and electrogenic heterologous exchange of aspartate with alanine. Thus, the asp operon confers a proton motive metabolic cycle consisting of the electrogenic aspartate-alanine antiporter and the aspartate decarboxylase, which keeps intracellular levels of alanine, the countersubstrate for aspartate, high.



1970 ◽  
Vol 48 (1) ◽  
pp. 133-146 ◽  
Author(s):  
J. A. Black ◽  
G. H. Dixon

Alpha chains of human haptoglobin have been prepared from whole haptoglobin of genetic type Hp 2–1 purified from the ascites fluid of a single patient. Amino acid sequence analysis has been carried out on these light chains which represent the products α1S and α2(F,S) of the single genes Hp1S and Hp2(F,S), and are, respectively, 83 and 142 residues in length. The data reported here concern the sequence analysis of two series of tryptic peptides, one obtained by unlimited cleavage of the chains by p-toluene sulfonamido-phenylethyl chloromethyl ketone - trypsin, and the second following limitation of trypsin cleavage to arginyl residues after modification of lysyl residues by trifluoracetylation. The major technique for sequence analysis of these peptides was a modification of the p-dimethylaminonaphthalene-sulfonyl-Edman (dansyl-Edman) procedure employing a new thin-layer chromatographic separation of the dansyl-amino acids. The sequences of these tryptic peptides in conjunction with those of the chymotryptic peptides allowed the unequivocal deduction of portions of the sequence, but the final overlaps were provided by fragments obtained by specific chemical cleavage of the chain at aspartyl residues. The amino acid sequences deduced have documented the occurrence of a partial gene duplication in the gene product α2(F,S) of the Hp2(F,S) gene.



1985 ◽  
Vol 38 (3) ◽  
pp. 221 ◽  
Author(s):  
AT Gilbert ◽  
EOP Thompson

The amino acid sequence of the iJ-chain of the principal haemoglobin from A. trapezia has been determined. The sequence was deduced from the sequences of tryptic peptides, which were fractionated using highperformance liquid chromatography and peptide mapping. Additional sequence data, particularly for the large tryptic peptides, was obtained from enzyme digests of both cyanogen bromide fragments and large citraconyitryptic peptides.



2000 ◽  
Vol 68 (5) ◽  
pp. 2720-2727 ◽  
Author(s):  
Robert A. Kingsley ◽  
Karin van Amsterdam ◽  
Naomi Kramer ◽  
Andreas J. Bäumler

ABSTRACT Little is known about factors which enable Salmonellaserotypes to circulate within populations of livestock and domestic fowl. We have identified a DNA region which is present inSalmonella serotypes commonly isolated from livestock and domestic fowl (S. enterica subspecies I) but absent from reptile-associated Salmonella serotypes (S. bongori and S. enterica subspecies II to VII). This DNA region was cloned from Salmonella serotype Typhimurium and sequence analysis revealed the presence of a 6,105-bp open reading frame, designated shdA, whose product's deduced amino acid sequence displayed homology to that of AIDA-I from diarrheagenicEscherichia coli, MisL of serotype Typhimurium, and IcsA ofShigella flexneri. The shdA gene was located adjacent to xseA at 52 min, in a 30-kb DNA region which is not present in Escherichia coli K-12. A serotype Typhimurium shdA mutant was shed with the feces in reduced numbers and for a shorter period of time compared to its isogenic parent. A possible role for the shdA gene during the expansion in host range of S. enterica subspecies I to include warm-blooded vertebrates is discussed.



1985 ◽  
Vol 50 (4) ◽  
pp. 885-896 ◽  
Author(s):  
Bedřich Meloun ◽  
Miroslav Baudyš ◽  
Manfred Pavlík ◽  
Vladimír Kostka ◽  
Gert Hausdorf ◽  
...  

The large cyanogen bromide fragment (CB1) represents the N-terminal part of the molecule of thermitase and contains 226 amino acid residues. Its molecular weight calculated from sequential data is 22 932 (the C-terminal residue is regarded as a methionine residue in the calculations). The amino acid sequence of fragment CB1 was determined by analysis of peptides obtained by tryptic hydrolysis of the fragment; these data were complemented by sequence analysis of the chymotryptic digest of fragment Mf (residues 75 through 226) and of chymotryptic fragment ET3 (residues 103 through 226) isolated from the limited tryptic digest of fragment CB1. The peptides were purified by high performance liquid chromatography and by thin layer techniques. The sequence analysis of the large peptides was effected in the sequenator, small peptides were sequenced manually by the DABITC/PITC double coupling technique. The results obtained in this study together with those of previous work5 permitted the complete amino acid sequence of fragment CB1 to be determined.



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