Cloning and Characterization of Three Genes Encoding LMW-GSs from Triticum aestivum, Cultival Cheyenne

2012 ◽  
Vol 554-556 ◽  
pp. 1116-1120 ◽  
Author(s):  
Mei Rong Chen ◽  
Xing Shen ◽  
Lin Li ◽  
Song Qing Hu

Three low molecular weight subunit genes, named LMW-CND1 (GeneBank accession JQ780048), LMW-CND2 (GeneBank accession JQ779840), LMW-CND3 (GeneBank accession JQ779841), with a ORF of 1053 bp, 903 bp, 969 bp, respectively, were isolated from cv. Cheyenne and characterized detailed in molecular level. The proteins encoded by the genes, with 350, 300, 322 amino acid residues respectively, differ only in repetitive domain of sequences due to insertion or deletion of repeats in this domain. Highly similarity in amino-acid sequence between these three subunits and other published LMW-GSs was also observed, showing that all three genes published here are typical LMW-GS genes and closely related to the genes on chromosome 1D. Besides, secondary structure prediction of proteins indicated that, in the three LMW-GSs, random loop accounts for no less than 70 %, α-helix amounts to 26 %, average, and only 1.4 %~1.7 % is β-sheet.

1997 ◽  
Vol 87 (2) ◽  
pp. 154-160 ◽  
Author(s):  
Hui-Fen Zhang ◽  
Leonard J. Francl ◽  
James G. Jordahl ◽  
Steven W. Meinhardt

Cultivar-specific toxic metabolites of Pyrenophora tritici-repentis are involved in the appearance of necrotic and chlorotic foliar lesions characteristic of tan spot. A P. tritici-repentis necrosis-inducing toxin, Ptr necrosis toxin, was purified from isolate 86-124, sequenced by gas-phase amino acid microsequencing, and characterized by circular dichroism (CD) spectroscopy and isoelectric focusing. The purified protein had a similar amino acid composition and molecular weight as previously reported. Analysis of the CD spectrum from 178 to 250 nm indicated a protein consisting of 13% α-helix, 36% antiparallel β-sheet, 25% turns, and 25% other structures. The Ptr necrosis toxin from isolate 86-124 has an isoelectric point near pH 10. Using overlapping proteolytic fragments obtained from the toxin, a sequence of 101 continuous amino acids was obtained, but the amino terminus was blocked and 9 to 16 amino acids could not be sequenced. Secondary structure prediction based on the amino acid sequence indicated a β-sheet protein with little α-helix, which is in agreement with the structure determined by CD spectroscopy. Sequence analysis indicated the presence of a possible membrane adhesion site and several possible phosphorylation sites that may be involved in phytotoxicity.


2021 ◽  
Vol 12 ◽  
Author(s):  
Kazuya Yamanaka ◽  
Ryo Ozaki ◽  
Yoshimitsu Hamano ◽  
Tadao Oikawa

We recently disclosed that the biosynthesis of antiviral γ-poly-D-2,4-diaminobutyric acid (poly-D-Dab) in Streptoalloteichus hindustanus involves an unprecedented cofactor independent stereoinversion of Dab catalyzed by PddB, which shows weak homology to diaminopimelate epimerase (DapF). Enzymological properties and mechanistic details of this enzyme, however, had remained to be elucidated. Here, through a series of biochemical characterizations, structural modeling, and site-directed mutageneses, we fully illustrate the first Dab-specific PLP-independent racemase PddB and further provide an insight into its evolution. The activity of the recombinant PddB was shown to be optimal around pH 8.5, and its other fundamental properties resembled those of typical PLP-independent racemases/epimerases. The enzyme catalyzed Dab specific stereoinversion with a calculated equilibrium constant of nearly unity, demonstrating that the reaction catalyzed by PddB is indeed racemization. Its activity was inhibited upon incubation with sulfhydryl reagents, and the site-directed substitution of two putative catalytic Cys residues led to the abolishment of the activity. These observations provided critical evidence that PddB employs the thiolate-thiol pair to catalyze interconversion of Dab isomers. Despite the low levels of sequence similarity, a phylogenetic analysis of PddB indicated its particular relevance to DapF among PLP-independent racemases/epimerases. Secondary structure prediction and 3D structural modeling of PddB revealed its remarkable conformational analogy to DapF, which in turn allowed us to predict amino acid residues potentially responsible for the discrimination of structural difference between diaminopimelate and its specific substrate, Dab. Further, PddB homologs which seemed to be narrowly distributed only in actinobacterial kingdom were constantly encoded adjacent to the putative poly-D-Dab synthetase gene. These observations strongly suggested that PddB could have evolved from the primary metabolic DapF in order to organize the biosynthesis pathway for the particular secondary metabolite, poly-D-Dab. The present study is on the first molecular characterization of PLP-independent Dab racemase and provides insights that could contribute to further discovery of unprecedented PLP-independent racemases.


Author(s):  
Joëlle De Meutter ◽  
Erik Goormaghtigh

AbstractPrediction of protein secondary structure from FTIR spectra usually relies on the absorbance in the amide I–amide II region of the spectrum. It assumes that the absorbance in this spectral region, i.e., roughly 1700–1500 cm−1 is solely arising from amide contributions. Yet, it is accepted that, on the average, about 20% of the absorbance is due to amino acid side chains. The present paper evaluates the contribution of amino acid side chains in this spectral region and the potential to improve secondary structure prediction after correcting for their contribution. We show that the β-sheet content prediction is improved upon subtraction of amino acid side chain contributions in the amide I–amide II spectral range. Improvement is relatively important, for instance, the error of prediction of β-sheet content decreases from 5.42 to 4.97% when evaluated by ascending stepwise regression. Other methods tested such as partial least square regression and support vector machine have also improved accuracy for β-sheet content evaluation. The other structures such as α-helix do not significantly benefit from side chain contribution subtraction, in some cases prediction is even degraded. We show that co-linearity between secondary structure content and amino acid composition is not a main limitation for improving secondary structure prediction. We also show that, even though based on different criteria, secondary structures defined by DSSP and XTLSSTR both arrive at the same conclusion: only the β-sheet structure clearly benefits from side chain subtraction. It must be concluded that side chain contribution subtraction benefit for the evaluation of other secondary structure contents is limited by the very rough description of side chain absorbance which does not take into account the variations related to their environment. The study was performed on a large protein set. To deal with the large number of proteins present, we worked on protein microarrays deposited on BaF2 slides and FTIR spectra were acquired with an imaging system.


2009 ◽  
Vol 42 (3) ◽  
pp. 540-544 ◽  
Author(s):  
Michihiro Sugahara ◽  
Yukuhiko Asada ◽  
Hiroki Shimada ◽  
Hideyuki Taka ◽  
Naoki Kunishima

HATODAS II is the second version of HATODAS (the Heavy-Atom Database System), which suggests potential heavy-atom reagents for the derivatization of protein crystals. The present expanded database contains 3103 heavy-atom binding sites, which is four times more than the previous version. HATODAS II has three new criteria to evaluate the feasibility of the search results: (1) potentiality scoring for the predicted heavy-atom reagents, (2) exclusion of the disordered amino acid residues based on the secondary structure prediction and (3) consideration of the solvent accessibility of amino acid residues from a homology model. In the point mutation option, HATODAS II suggests possible mutation sites into reactive amino acid residues such as Met, Cys and His, on the basis of multiple sequence alignments of homologous proteins. These new features allow the user to make a well informed decision as to the possible heavy-atom derivatization experiments of protein crystals.


2012 ◽  
Vol 79 (4) ◽  
pp. 1378-1384 ◽  
Author(s):  
Kentaro Isotani ◽  
Junji Kurokawa ◽  
Fumiko Suzuki ◽  
Syunsuke Nomoto ◽  
Takashi Negishi ◽  
...  

ABSTRACTWe used the resting-cell reaction to screen approximately 200 microorganisms for biocatalysts which reduce 3-quinuclidinone to optically pure (R)-(−)-3-quinuclidinol.Microbacterium luteolumJCM 9174 was selected as the most suitable organism. The genes encoding the protein products that reduced 3-quinuclidinone were isolated fromM. luteolumJCM 9174. ThebacCgene, which consists of 768 nucleotides corresponding to 255 amino acid residues and is a constituent of the bacilysin synthetic gene cluster, was amplified by PCR based on homology to known genes. Theqnrgene consisted of 759 nucleotides corresponding to 252 amino acid residues. Both enzymes belong to the short-chain alcohol dehydrogenase/reductase (SDR) family. The genes were expressed inEscherichia colias proteins which were His tagged at the N terminus, and the recombinant enzymes were purified and characterized. Both enzymes showed narrow substrate specificity and high stereoselectivity for the reduction of 3-quinuclidinone to (R)-(−)-3-quinuclidinol.


2011 ◽  
Vol 32 (11) ◽  
pp. 4106-4108 ◽  
Author(s):  
Hyun-Dong Do ◽  
Hyun-Joo Jo ◽  
Dong-Hyeon Jo ◽  
Kwang-Hoon Kong

1989 ◽  
Vol 259 (2) ◽  
pp. 453-461 ◽  
Author(s):  
G J Price ◽  
P Jones ◽  
M D Davison ◽  
B Patel ◽  
R Bendori ◽  
...  

We have determined the complete sequence of chick vinculin from two overlapping cDNA clones. The vinculin mRNA consists of 262 bp of 5' untranslated sequence, an open reading frame of 3195 bp (excluding the initiation codon) and a long 3' untranslated sequence (greater than 2 kb). Chick vinculin contains 1066 amino acid residues, and has a deduced molecular mass of 116,933 Da. Analysis of the domain structure of vinculin shows that the molecule can be cleaved by V8 proteinase into a 90 kDa globular head and a 32 kDa tail region, the latter of which could further be cleaved into a 27 kDa polypeptide. The 90 kDa globular head contains the N-terminus of vinculin, three 112-residue repeats (residues 259-589), and extends to approximately residue 850. Gel overlay experiments show that it also contains a binding site for the cytoskeletal protein talin. The talin-binding domain was further localized to the N-terminal 398 amino acid residues of the protein by expression in vitro of this region from a vinculin cDNA cloned into the Bluescript SK+ vector. The head and tail domains are apparently separated by a proline-rich region that contains V8-proteinase-cleavage sites and a candidate tyrosine (822)-phosphorylation site. Secondary-structure prediction suggests that the head and tail domains contain alpha-helical regions separated by short stretches of turn/coil. Comparison of the chick with a partial human sequence reveals that vinculin is a highly conserved protein. In chickens Southern-blot analysis is consistent with a single vinculin gene, and it is therefore likely that vinculin, and its higher-molecular-mass isoform termed metavinculin, arise through alternative splicing.


2019 ◽  
Vol 73 (8) ◽  
pp. 511-513 ◽  
Author(s):  
Kritsada Singha ◽  
Rossarin Karnpean ◽  
Goonnapa Fucharoen ◽  
Supan Fucharoen

We describe a dominant β-thalassaemia caused by a deletion of G at nucleotide position 364 in exon 3 of the β-globin gene. The heterozygosity of this mutation was found in a 36-year-old Thai patient who had moderate hypochromic microcytic anaemia with haemolytic blood picture. Haemoglobin (Hb) analysis revealed relatively higher Hbs A2 (6.8%) and F (4.7%) as compared with those of β0-thalassaemia (n=278) and β+-thalassaemia (n=55) carriers in our series. Secondary structure prediction of the elongated β-globin chain showed that the α-helix at the C-terminal is disrupted dramatically by the random coil and β-sheet, which should result in a highly unstable β-globin variant, undetectable in peripheral blood and a dominant clinical phenotypic feature.


2003 ◽  
Vol 47 (10) ◽  
pp. 3187-3194 ◽  
Author(s):  
Antonio J. Martín-Galiano ◽  
Luz Balsalobre ◽  
Asunción Fenoll ◽  
Adela G. de la Campa

ABSTRACT Two clinical isolates of viridans group streptococci (VS) with different degrees of susceptibility to optochin (OPT), i.e., fully OPT-susceptible (Opts) VS strain 1162/99 (for which the MIC was equal to that for Streptococcus pneumoniae, 0.75 μg/ml) and intermediate Opts VS strain 1174/97 (MIC, 6 μg/ml) were studied. Besides being OPT susceptible, they showed characteristics typical of VS, such as bile insolubility; lack of reaction with pneumococcal capsular antibodies; and lack of hybridization with rRNA (AccuProbe)-, lytA-, and pnl-specific pneumococcal probes. However, these VS Opts strains and VS type strains hybridized with ant, a gene not present in S. pneumoniae. A detailed characterization of the genes encoding the 16S rRNA and SodA classified isolates 1162/99 and 1174/97 as Streptococcus mitis. Analysis of the atpCAB region, which encodes the c, a, and b subunits of the F0F1 H+-ATPase, the target of optochin, revealed high degrees of similarity between S. mitis 1162/99 and S. pneumoniae in atpC, atpA, and the N terminus of atpB. Moreover, amino acid identity between S. mitis 1174/97 and S. pneumoniae was found in α helix 5 of the a subunit. The organization of the chromosomal region containing the atp operon of the two Opts VS and VS type strains was spr1284-atpC, with spr1284 being located 296 to 556 bp from atpC, whereas in S. pneumoniae this distance was longer than 68 kb. In addition, the gene order in S. pneumoniae was IS1239-74 bp-atpC. The results suggest that the full OPT susceptibility of S. mitis 1162/99 is due to the acquisition of atpC, atpA, and part of atpB from S. pneumoniae and that the intermediate OPT susceptibility of S. mitis 1174/97 correlates with the amino acid composition of its a subunit.


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Zhongying Wang ◽  
Qixuan Wang ◽  
Hao Wu ◽  
Zhiwu Huang

Abstract Background Prestin (SLC26A5) is responsible for acute sensitivity and frequency selectivity in the vertebrate auditory system. Limited knowledge of prestin is from experiments using site-directed mutagenesis or domain-swapping techniques after the amino acid residues were identified by comparing the sequence of prestin to those of its paralogs and orthologs. Frog prestin is the only representative in amphibian lineage and the studies of it were quite rare with only one species identified. Results Here we report a new coding sequence of SLC26A5 for a frog species, Rana catesbeiana (the American bullfrog). In our study, the SLC26A5 gene of Rana has been mapped, sequenced and cloned successively using RNA-Seq. We measured the nonlinear capacitance (NLC) of prestin both in the hair cells of Rana’s inner ear and HEK293T cells transfected with this new coding gene. HEK293T cells expressing Rana prestin showed electrophysiological features similar to that of hair cells from its inner ear. Comparative studies of zebrafish, chick, Rana and an ancient frog species showed that chick and zebrafish prestin lacked NLC. Ancient frog’s prestin was functionally different from Rana. Conclusions We mapped and sequenced the SLC26A5 of the Rana catesbeiana from its inner ear cDNA using RNA-Seq. The Rana SLC26A5 cDNA was 2292 bp long, encoding a polypeptide of 763 amino acid residues, with 40% identity to mammals. This new coding gene could encode a functionally active protein conferring NLC to both frog HCs and the mammalian cell line. While comparing to its orthologs, the amphibian prestin has been evolutionarily changing its function and becomes more advanced than avian and teleost prestin.


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