scholarly journals Identification of C-terminal amino acid residues of cauliflower mosaic virus open reading frame III protein responsible for its DNA binding activity.

1993 ◽  
Vol 90 (4) ◽  
pp. 1470-1473 ◽  
Author(s):  
J. L. Mougeot ◽  
T. Guidasci ◽  
T. Wurch ◽  
G. Lebeurier ◽  
J. M. Mesnard
1995 ◽  
Vol 309 (2) ◽  
pp. 543-550 ◽  
Author(s):  
G S Long ◽  
J M Bryant ◽  
P W Taylor ◽  
J P Luzio

Bacteriophage E specifically recognizes and infects strains of Escherichia coli which display the alpha-2,8-linked polysialic acid K1 capsule. Bacteriophage E endosialidase, which is thought to be responsible for initial absorption of the phage to the host bacterium, was purified, and the N-terminal amino acid sequences of the polypeptide monomer and cyanogen bromide fragments were determined. Synthetic oligonucleotide probes were designed from the N-terminal amino acid sequences and used to identify restriction fragments of bacteriophage E DNA encoding the endosialidase. The primary nucleotide sequence of the bacteriophage E endosialidase gene contains an open reading frame encoding a 90 kDa polypeptide which is processed to give a mature 74 kDa protein. The native enzyme is probably a trimer of identical 74 kDa subunits. In the bacteriophage E genome the K1E endosialidase open reading frame is preceded by a putative upstream promoter region with homology to a bacteriophage SP6 promoter. A central region of 500 amino acids of the deduced protein sequence of the K1E endosialidase was found to have 84% identity to K1F endosialidase. Both endosialidases contain two copies of a sialidase sequence motif common to many bacterial and viral sialidases. These sequences flank the region of greatest identity between the two endosialidase forms, which suggests that this central domain is involved in binding and hydrolysis of the polysialic acid substrate.


2006 ◽  
Vol 87 (11) ◽  
pp. 3329-3338 ◽  
Author(s):  
Tomoichiro Oka ◽  
Mami Yamamoto ◽  
Kazuhiko Katayama ◽  
Grant S. Hansman ◽  
Satoko Ogawa ◽  
...  

Sapovirus (SaV), a member of the family Caliciviridae, is a causative agent of acute gastroenteritis in humans and swine and is currently divided into five genogroups, GI–GV. The proteolytic processing of the SaV open reading frame 1 (ORF1) polyprotein with a human GII SaV Mc10 strain has recently been determined and the products are arranged in the following order: NH2–p11–p28–p35 (NTPase)–p32–p14 (VPg)–p70 (Pro–Pol)–p60 (VP1)–COOH. The cleavage site between p14 (VPg) and p70 (Pro–Pol) was identified as E1055/A1056 by N-terminal amino acid sequencing. To identify other cleavage sites, a series of GII SaV Mc10 full-length clones containing disrupted potential cleavage sites in the ORF1 polyprotein were constructed and used to generate linear DNA templates for in vitro coupled transcription–translation. The translation products were analysed by SDS-PAGE or by immunoprecipitation with region-specific antibodies. N-terminal amino acid sequencing with Escherichia coli-expressed recombinant proteins was also used to identify the cleavage site between p32 and p14. These approaches enabled identification of the six cleavage sites of the Mc10 ORF1 polyprotein as E69/G70, Q325/G326, Q666/G667, E940/A941, E1055/A1056 and E1722/G1723. The alignment of the SaV full-length ORF1 amino acid sequences indicated that the dipeptides used for the cleavage sites were either E or Q at the P1 position and A, G or S at the P1′ position, which were conserved in the GI, GII, GIII, GIV and GV SaV ORF1 polyprotein.


Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 715
Author(s):  
Tamara Tomanić ◽  
Claire Martin ◽  
Holly Stefen ◽  
Esmeralda Parić ◽  
Peter Gunning ◽  
...  

Tropomyosins (Tpms) have been described as master regulators of actin, with Tpm3 products shown to be involved in early developmental processes, and the Tpm3 isoform Tpm3.1 controlling changes in the size of neuronal growth cones and neurite growth. Here, we used primary mouse hippocampal neurons of C57/Bl6 wild type and Bl6Tpm3flox transgenic mice to carry out morphometric analyses in response to the absence of Tpm3 products, as well as to investigate the effect of C-terminal truncation on the ability of Tpm3.1 to modulate neuronal morphogenesis. We found that the knock-out of Tpm3 leads to decreased neurite length and complexity, and that the deletion of two amino acid residues at the C-terminus of Tpm3.1 leads to more detrimental changes in neurite morphology than the deletion of six amino acid residues. We also found that Tpm3.1 that lacks the 6 C-terminal amino acid residues does not associate with stress fibres, does not segregate to the tips of neurites, and does not impact the amount of the filamentous actin pool at the axonal growth cones, as opposed to Tpm3.1, which lacks the two C-terminal amino acid residues. Our study provides further insight into the role of both Tpm3 products and the C-terminus of Tpm3.1, and it forms the basis for future studies that aim to identify the molecular mechanisms underlying Tpm3.1 targeting to different subcellular compartments.


2017 ◽  
Vol 65 (35) ◽  
pp. 7705-7712 ◽  
Author(s):  
Long Ding ◽  
Liying Wang ◽  
Zhipeng Yu ◽  
Sitong Ma ◽  
Zhiyang Du ◽  
...  

1970 ◽  
Vol 120 (2) ◽  
pp. 417-424 ◽  
Author(s):  
A. P. Fletcher ◽  
A. Neuberger ◽  
Wendy A. Ratcliffe

1. A revised amino acid and carbohydrate composition of human Tamm–Horsfall glycoprotein is presented. 2. No significant differences were obtained in the amino acid composition of Tamm–Horsfall glycoprotein isolated from patients with cystic fibrosis. 3. The glycoprotein was shown to possess a high half-cystine content of 1 per 11–12 amino acid residues, which has been confirmed by performic acid oxidation and S-alkylation with iodoacetate and iodoacetamide. No thiol groups were detected in the glycoprotein. 4. Treatment of the glycoprotein with 0.5m-sodium hydroxide at 4°C for 2 days did not release heterosaccharide material, which suggests that the predominant carbohydrate–protein linkages present are not of the O-glycosidic type. 5. No N-terminal amino acid was detected in the glycoprotein.


1995 ◽  
Vol 15 (10) ◽  
pp. 5329-5338 ◽  
Author(s):  
K Onel ◽  
M P Thelen ◽  
D O Ferguson ◽  
R L Bennett ◽  
W K Holloman

The REC1 gene of Ustilago maydis has an uninterrupted open reading frame, predicted from the genomic sequence to encode a protein of 522 amino acid residues. Nevertheless, an intron is present, and functional activity of the gene in mitotic cells requires an RNA processing event to remove the intron. This results in a change in reading frame and production of a protein of 463 amino acid residues. The 3'-->5' exonuclease activity of proteins derived from the REC1 genomic open reading frame, the intronless open reading frame, and several mutants was investigated. The mutants included a series of deletions constructed by removing restriction fragments at the 3' end of the cloned REC1 gene and a set of mutant alleles previously isolated in screens for radiation sensitivity. All of these proteins were overproduced in Escherichia coli as N-terminal polyhistidine-tagged fusions that were subsequently purified by immobilized metal affinity chromatography and assayed for 3'-->5' exonuclease activity. The results indicated that elimination of the C-terminal third of the protein did not result in a serious reduction in 3'-->5' exonuclease activity, but deletion into the midsection caused a severe loss of activity. The biological activity of the rec1-1 allele, which encodes a truncated polypeptide with full 3'-->5' exonuclease activity, and the rec1-5 allele, which encodes a more severely truncated polypeptide with no exonuclease activity, was investigated. The two mutants were equally sensitive to the lethal effect of UV light, but the spontaneous mutation rate was elevated 10-fold over the wild-type rate in the rec1-1 mutant and 100-fold in the rec1-5 mutant. The elevated spontaneous mutation rate correlated with the ablation of exonuclease activity, but the radiation sensitivity did not. These results indicate that the C-terminal portion of the Rec1 protein is not essential for exonuclease activity but is crucial in the role of REC1 in DNA damage repair.


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