scholarly journals Identification of the conserved domains of ADP-Glucose Pyrophosphorylase (AGPase) protein in sweetpotato (Ipomoea batatas (L.) Lam.) and its two wild relatives

Author(s):  
Hualin Nie ◽  
Sujung Kim ◽  
Hohyun Kim ◽  
Ji-Seong Kim ◽  
Sun-Hyung Kim

Abstract The conserved domains are defined as recurring units in molecular evolution, which are commonly used to interpret the molecular function and biochemical structure of proteins. The AGPase amino acid sequences of three species from the Ipomoea genus were identified to investigate their physicochemical and biochemical characteristics. The molecular weights (MW), isoelectric point (pI), instability index (II), and grand average of hydropathy (GRAVY) showed considerable differences in each plant. The aliphatic index (AI) values of sweetpotato AGPase proteins were higher in the small subunit than in the large subunit. The AGPase proteins from sweetpotato contain an LbH_G1P_AT_C domain in the C-terminal region and various domains (NTP_transferase, ADP_Glucose_PP, or Glyco_tranf_GTA) in the N-terminal region. On the other hand, most of its two relatives (I. trifida and I. triloba) only contain the NTP_transferase domain in the N-terminal region. These findings suggested that these conserved domains were species specificity and related to the subunit types of AGPase proteins. The study may enable research on the AGPase-related specific characteristics of sweetpotatoes, which do not exist in the other two species, such as starch metabolism and tuberization mechanism.

1998 ◽  
Vol 180 (5) ◽  
pp. 1194-1199 ◽  
Author(s):  
Juanito V. Parales ◽  
Rebecca E. Parales ◽  
Sol M. Resnick ◽  
David T. Gibson

ABSTRACT Biotransformations with recombinant Escherichia coliexpressing the genes encoding 2-nitrotoluene 2,3-dioxygenase (2NTDO) from Pseudomonas sp. strain JS42 demonstrated that 2NTDO catalyzes the dihydroxylation and/or monohydroxylation of a wide range of aromatic compounds. Extremely high nucleotide and deduced amino acid sequence identity exists between the components from 2NTDO and the corresponding components from 2,4-dinitrotoluene dioxygenase (2,4-DNTDO) from Burkholderia sp. strain DNT (formerlyPseudomonas sp. strain DNT). However, comparisons of the substrates oxidized by these dioxygenases show that they differ in substrate specificity, regiospecificity, and the enantiomeric composition of their oxidation products. Hybrid dioxygenases were constructed with the genes encoding 2NTDO and 2,4-DNTDO. Biotransformation experiments with these hybrid dioxygenases showed that the C-terminal region of the large subunit of the oxygenase component (ISPα) was responsible for the enzyme specificity differences observed between 2NTDO and 2,4-DNTDO. The small subunit of the terminal oxygenase component (ISPβ) was shown to play no role in determining the specificities of these dioxygenases.


1971 ◽  
Vol 125 (4) ◽  
pp. 1091-1107 ◽  
Author(s):  
P J Ford

1. The preparation of ribosomes and ribosomal subunits from Xenopus ovary is described. 2. The yield of once-washed ribosomes (buoyant density in caesium chloride 1.601g·cm-3; 44% RNA, 56% protein by chemical methods) was 10.1mg/g wet wt. of tissue. 3. Buoyant density in caesium chloride and RNA/protein ratios by chemical methods have been determined for ribosome subunits produced by 1.0mm-EDTA or 0.5m-potassium chloride treatment and also for EDTA subunits extracted with 0.5m-, 1.0m- or 1.5m-potassium chloride, 4. Analysis of ribosomal protein on acrylamide gels at pH4.5 in 6m-urea reveals 24 and 26 bands from small and large EDTA subunits respectively. The actual numbers of proteins are greater than this, as many bands are obviously doublets. 5. Analysis of the proteins in the potassium chloride extract and particle fractions showed that some bands are completely and some partially extracted. Taking partial extraction as an indication of possible doublet bands it was found that there were 12 and 20 such bands in the small and large subunits respectively, making totals of 36 and 46 proteins. 6. From the measured protein contents and assuming weight-average molecular weights for the proteins of large and small subunits close to those observed for eukaryote ribosomal proteins it is possible to compute the total numbers of protein molecules per particle. It appears that too few protein bands have been identified on acrylamide gels to account for all the protein in the large subunit, but probably enough for the small subunit.


1983 ◽  
Vol 31 (4) ◽  
pp. 395 ◽  
Author(s):  
PG Martin ◽  
AC Jennings

Ribulose bisphosphate carboxylase has been prepared from 50 species of angiosperms from 16 diverse families. In 35 preparations, well known 'bland leaf' methods were used but 15 species had 'pungent leaves' and for these a new preparative method is described. Automatic methods have been used to obtain N-terminal sequences (40 amino acids) of the small subunit (SSU) from all 50 species and the pattern of variability is discussed: 26 of 40 positions are variable to a degree similar to that found in plastocyanin and plant cytochrome c, i.e, an average of 3.7 different amino acids per variable site. These results, and the fact that sufficient protein can be obtained from 100 g of leaves, make a widespread phylogenetic survey of angiosperm SSU feasible and it is claimed that the method is at least as practicable as nucleic acid sequencing. A limited amount of sequencing has been carried out on the large subunit (LSU) but its low variability discourages a protein sequencing survey. Implications for gene structure and function are discussed and evidence is given that active LSU is derived from a precursor with 14 additional amino acids at the N-terminus. In SSU, variability of the two N- terminal amino acids suggests that they are not involved in the signals for removal of either the transit peptide or, in the RNA, of the intron, excision of one end of which depends on the codons for the invariable amino acids at positions 3 and 4. Evidence is also given that if the N-terminus of SSU is methionine, as is common, then it is modified and associated with a 'frayed' N-terminus.


1999 ◽  
Vol 181 (13) ◽  
pp. 3935-3941 ◽  
Author(s):  
Kempton M. Horken ◽  
F. Robert Tabita

ABSTRACT Form I ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) of the Calvin-Benson-Bassham cycle may be divided into two broad phylogenetic groups, referred to as red-like and green-like, based on deduced large subunit amino acid sequences. Unlike the form I enzyme from the closely related organism Rhodobacter sphaeroides, the form I RubisCO from R. capsulatus is a member of the green-like group and closely resembles the enzyme from certain chemoautotrophic proteobacteria and cyanobacteria. As the enzymatic properties of this type of RubisCO have not been well studied in a system that offers facile genetic manipulation, we purified theR. capsulatus form I enzyme and determined its basic kinetic properties. The enzyme exhibited an extremely low substrate specificity factor, which is congruent with its previously determined sequence similarity to form I enzymes from chemoautotrophs and cyanobacteria. The enzymological results reported here are thus strongly supportive of the previously suggested horizontal gene transfer that most likely occurred between a green-like RubisCO-containing bacterium and a predecessor to R. capsulatus. Expression results from hybrid and chimeric enzyme plasmid constructs, made with large and small subunit genes fromR. capsulatus and R. sphaeroides, also supported the unrelatedness of these two enzymes and were consistent with the recently proposed phylogenetic placement of R. capsulatus form I RubisCO. The R. capsulatus form I enzyme was found to be subject to a time-dependent fallover in activity and possessed a high affinity for CO2, unlike the closely similar cyanobacterial RubisCO, which does not exhibit fallover and possesses an extremely low affinity for CO2. These latter results suggest definite approaches to elucidate the molecular basis for fallover and CO2 affinity.


2010 ◽  
Vol 76 (11) ◽  
pp. 3715-3722 ◽  
Author(s):  
Gary Vanzin ◽  
Jianping Yu ◽  
Sharon Smolinski ◽  
Vekalet Tek ◽  
Grant Pennington ◽  
...  

ABSTRACT Upon exposure to carbon monoxide, the purple nonsulfur photosynthetic bacterium Rubrivivax gelatinosus produces hydrogen concomitantly with the oxidation of CO according to the equation CO + H2O ↔ CO2 + H2. Yet little is known about the genetic elements encoding this reaction in this organism. In the present study, we use transposon mutagenesis and functional complementation to uncover three clustered genes, cooL, cooX, and cooH, in Rubrivivax gelatinosus putatively encoding part of a membrane-bound, multisubunit NiFe-hydrogenase. We present the complete amino acid sequences for the large catalytic subunit and its electron-relaying small subunit, encoded by cooH and cooL, respectively. Sequence alignment reveals a conserved region in the large subunit coordinating a binuclear [NiFe] center and a conserved region in the small subunit coordinating a [4Fe-4S] cluster. Protein purification experiments show that a protein fraction of 58 kDa molecular mass could function in H2 evolution mediated by reduced methyl viologen. Western blotting experiments show that the two hydrogenase subunits are detectable and accumulate only when cells are exposed to CO. The cooX gene encodes a putative Fe-S protein mediating electron transfer to the hydrogenase small subunit. We conclude that these three Rubrivivax proteins encompass part of a membrane-bound, multisubunit NiFe-hydrogenase belonging to the energy-converting hydrogenase (Ech) type, which has been found among diverse microbes with a common feature in coupling H2 production with proton pumping for energy generation.


1992 ◽  
Vol 70 (4) ◽  
pp. 715-723 ◽  
Author(s):  
J. J. Pasternak ◽  
B. R. Glick

The molecular evolution of the amino acid sequences of the mature small and large subunits of ribulose-1,5-bisphosphate carboxylase/oxygense (Rubisco) was determined. The dataset for each subunit consisted of sequences from 39 different taxa of which 22 are represented with sequence information for both subunits. Phylogenetic trees were reconstructed using distance matrix, parsimony and simultaneous alignment and phylogeny methods. For the small subunit, the latter two methods produced similar trees that differed from the topology of the distance matrix tree. For the large subunit, each of the three tree-building methods yielded a distinct tree. Except for the distance matrix small subunit tree, the tree-building methods produced topologies for the small and large subunit sequences from the nonflowering plant taxa that, for the most part, agree with current taxonomic schemes. With the full datasets, the lack of consistency both among the various trees and with conventional taxonomic relationships was most evident with the Rubisco sequences from angiosperms. It is unlikely that current tree-building methods will be able to reconstruct an unambiguous molecular evolution of either of the Rubisco subunits. Molecular trees, regardless of methodology, showed similar topologies for the small and large subunits from the 22 taxa from which both subunits have been sequenced, indicating that the subunits have changed to the same extent over time. In this case, similar trees were formed because only 4 of the 22 taxa were from dicots. Key words: ribulose-1,5-bisphosphate carboxylase/oxygenase, amino acid sequence, molecular evolution, phyletic trees.


2019 ◽  
Vol 16 (3) ◽  
pp. 210-221
Author(s):  
Sarita Devi ◽  
Savitri ◽  
Tilak Raj ◽  
Nikhil Sharma ◽  
Wamik Azmi

Background:L-glutaminase enzyme belongs to the family of hydrolases, those acting on carbon-nitrogen bonds other than peptide bonds, specifically in linear amides. Protein L-glutaminase, which converts amino acid glutamine to a glutamate residue, is useful as antileukemic agent, antiretroviral agent and a new food-processing enzyme.Objective:The sequences representing L-glutaminase from extremophiles were analyzed for different physico-chemical properties and to relate these observed differences to their extremophilic properties, phylogenetic tree construction and the evolutionary relationship among them.Methods:In this work, in silico analysis of amino acid sequences of extremophilic (thermophile, halophile and psychrophiles) proteins has been done. The physiochemical properties of these four groups of proteins for L-glutaminase also differ in number of amino acids, aliphatic index and grand average of hydropathicity (GRAVY).Result:The GRAVY was found to be significantly high in thermophilic (2.29 fold) and psychrophilic bacteria (3.3 fold) as compare to mesophilic bacteria. The amino acid Cys (C) was found to be statistically significant in mesophilic bacteria (approximately or more than 3 fold) as compared to the abundance of this amino acid in extremophilic bacteria.Conclusion:Multiple sequence alignment revealed the domain/motif for glutaminase that consists of Ser-74, Lys-77, Asn-126, Lys-268, and Ser-269, which is highly conserved in all microorganisms.


1991 ◽  
Vol 69 (5) ◽  
pp. 1053-1061 ◽  
Author(s):  
M. Okada ◽  
Y. Okabe ◽  
M. Kono ◽  
K. Nakayama ◽  
H. Satoh

Pyrenoids of Bryopsis maxima contained several minor components other than the large subunit (LS) and the small subunit of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco). Among the minor components, polypeptides of 95, 67, and 41 kDa reacted with an antibody against the LS polypeptide. Amino acid sequences of these polypeptides were determined and compared with that deduced from the LS gene (rbcL) screened from the chloroplast DNA library of B. maxima. The N-terminal sequence of the LS peptide was not post-translationally processed and was almost identical with those of the polypeptides of 91, 67, and 41 kDa. The starch grains surrounding the pyrenoids contained a polypeptide of 66 kDa that was assigned as starch synthase. Key words: Bryopsis maxima, nitrate reductase, pyrenoid, rbcL, Rubisco, starch synthase.


1989 ◽  
Vol 67 (10) ◽  
pp. 703-711 ◽  
Author(s):  
Kevin K. W. Wang ◽  
Basil D. Roufogalis ◽  
Antonio Villalobo

Calcineurin, a calmodulin-stimulated phosphatase from bovine brain, was hydrolyzed by calpain I from human erythrocytes. In the absence of calmodulin, calpain rapidly transformed the 60-kilodalton (kDa) catalytic subunit of calcineurin into a transient 57-kDa fragment and thereafter a 43-kDa limit fragment. In the presence of calmodulin, the 60-kDa subunit was sequentially proteolysed to a 55-kDa fragment and then a 49-kDa fragment. Upon proteolysis in the absence or presence of calmodulin, the p-nitrophenyl phosphatase activity (assayed in the presence of calmodulin) was increased by 300%. The 43- and the 49-kDa fragments were found to (i) remain associated with the small subunit (17 kDa), (ii) have lost the ability to bind and to be activated by calmodulin, and (iii) have phosphatase activity that was still stimulated by Mn2+ or Ni2+. The 43- + 17-kDa form had similar Km values for various substrates, but the Vmax values were increased compared with the native enzyme. It is proposed that (i) a 43-kDa core segment of the 60-kDa subunit of calcineurin contained the catalytic domain, the small subunit-binding domain, and the metal ion (Mn2+ and (or) Ni2+) binding site; and (ii) two distinct types of inhibitory domains exist near the end(s) of the large subunit, one of which is calmodulin regulated, while the other is calmodulin independent.Key words: calcineurim, calpain, calmodulin, phosphatase, protease.


1987 ◽  
Vol 33 (4) ◽  
pp. 339-343 ◽  
Author(s):  
Valsan Mandiyan ◽  
G. Ramananda Rao

The cytoplasmic ribosomal proteins of Microsporum canis were characterised in basic–acidic and basic–SDS two-dimensional polyacrylamide gel electrophoresis systems. The small subunit contained 28 proteins and the large subunit 38 proteins. The molecular weights of these proteins were in the range of 32 500 to 7600 and 48 000 to 11 000 in the small and large subunits, respectively. The 80S ribosomes showed 65 and 66 protein spots in basic–acidic and basic–SDS gel systems, respectively.


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