scholarly journals Characterization of cytoplasmic and chloroplast 5S ribosomal ribonucleic acid from broad-bean leaves

1971 ◽  
Vol 124 (1) ◽  
pp. 83-89 ◽  
Author(s):  
P. I. Payne ◽  
T. A. Dyer

Green leaves of the broad bean (Vicia faba) contain two 5S RNA components that can be separated from each other by polyacrylamide-gel electrophoresis. The major component is located in the larger subunit of cytoplasmic ribosomes, whereas the minor component occurs in the larger subunit of chloroplast ribosomes. Their electrophoretic mobilities relative to those of Escherichia coli 5S RNA (120 nucleotides) and plant 4S RNA (78 nucleotides) suggest that they consist of 118 and 122 nucleotide residues respectively. Thermal ‘melting‘ profiles of plant cytoplasmic and chloroplast 5S RNA species at 260nm indicate the similarity of their secondary structures, not only to each other, but also to those of E. coli and mammalian 5S RNA species. The base compositions of the two plant 5S RNA species have more in common with each other than with the corresponding molecules from either E. coli or mammalian cells.

1983 ◽  
Vol 61 (12) ◽  
pp. 1315-1321 ◽  
Author(s):  
Peter C. Loewen ◽  
Barbara L. Triggs ◽  
Glen R. Klassen ◽  
Joel H. Weiner

A hybrid Escherichia coli: Col E1 plasmid, pLC36-19, containing a catalase gene has been identified in the Clarke and Carbon colony bank. Catalase activity was amplified two- to three-fold in the pLC36-19-containing strain relative to other hybrid-plasmid-containing strains and this activity could be induced three- or four-fold by hydrogen peroxide or ascorbic acid. The plasmid was transferred to a strain chromosomally deficient in catalase synthesis, resulting in a strain with high and inducible levels of catalase. The plasmid was also transferred to a minicell-producing strain and minicells harbouring the plasmid were found to synthesize a labelled protein with a molecular weight of 84 000 characteristic of catalase from E. coli. A catalase activity was also synthesized by the plasmid-containing minicells. Two catalase activities with associated peroxidase activities coded for by the plasmid were separable by polyacrylamide gel electrophoresis and migrated coincident with chromosomally encoded catalase–peroxidase activities. A third catalase activity which did not have an associated peroxidase activity was not coded for by the plasmid. A physical map of the 25.5-kilobase pair plasmid was constructed by restriction nuclease analysis and the relative positions of 38 restriction sites were defined.


1994 ◽  
Vol 298 (3) ◽  
pp. 727-732 ◽  
Author(s):  
K Ford ◽  
J Waltho ◽  
D Hornby

We have previously reported the identification of a novel activity residing in the nuclear fraction of mammalian cells that selectively binds and hydrolyses deoxyribonucleoside triphosphates. Incubation of this protein with [alpha-32P]dATP leads to the appearance of a retarded band relative to free dATP when the reaction is analysed on non-denaturing polyacrylamide gels. We now show that the retarded species comprises the product of dATP hydrolysis (dADP or dAMP) bound to an as yet unidentified species. We have termed this complex the ‘product-nucleotide binding particle’ or PNBP*. Through a combination of continuous elution polyacrylamide-gel electrophoresis and gel-filtration chromatography, we demonstrate that the hydrolytic activity (dNTPase) is distinct from the radiolabelled species detected in gel-retardation experiments. T.l.c. confirms that the labelled product does not share RF values associated with a range of mono-, di- and tri-phosphate deoxyribonucleotide standards, and gel-filtration experiments suggest a molecular mass for PNBP* of between 2.5 and 3 kDa. The ability of purified PNBP* to retain its nucleotide ligand after a number of denaturing processes suggests that the ligand is covalently bound. The recovery of dNTPase activity from both gel-filtration and ion-exchange chromatography reveals that the as yet unliganded PNBP* (or a precursor form) is associated with the dNTPase enzyme as part of the active complex, prior to addition of dATP.


2002 ◽  
Vol 70 (6) ◽  
pp. 2891-2898 ◽  
Author(s):  
Yukie Shibata ◽  
Yoshihisa Yamashita ◽  
Kazuhisa Ozaki ◽  
Yoshio Nakano ◽  
Toshihiko Koga

ABSTRACT Six genes (rgpA through rgpF) that were involved in assembling the rhamnose-glucose polysaccharide (RGP) in Streptococcus mutans were previously identified (Y. Yamashita, Y. Tsukioka, K. Tomihisa, Y. Nakano, and T. Koga, J. Bacteriol. 180:5803-5807, 1998). The group-specific antigens of Lancefield group A, C, and E streptococci and the polysaccharide antigen of Streptococcus sobrinus have the same rhamnan backbone as the RGP of S. mutans. Escherichia coli harboring plasmid pRGP1 containing all six rgp genes did not synthesize complete RGP. However, E. coli carrying a plasmid with all of the rgp genes except for rgpE synthesized the rhamnan backbone of RGP without glucose side chains, suggesting that in addition to rgpE, another gene is required for glucose side-chain formation. Synthesis of the rhamnan backbone in E. coli required the initiation of transfer of N-acetylglucosamine to a lipid carrier and the expression of the rgpC and rgpD genes encoding the putative ABC transporter specific for RGP. The similarities in RGP synthesis between E. coli and S. mutans suggest common pathways for rhamnan synthesis. Therefore, we evaluated the rhamnosyl polymerization process in E. coli by high-resolution sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the lipooligosaccharide (LOS). An E. coli transformant harboring rgpA produced the LOS modified by the addition of a single rhamnose residue. Furthermore, the rgpA, rgpB, and rgpF genes of pRGP1 were independently mutated by an internal deletion, and the LOS chemotypes of their transformants were examined. The transformant with an rgpA deletion showed the same LOS profile as E. coli without a plasmid. The transformant with an rgpB deletion showed the same LOS profile as E. coli harboring rgpA alone. The transformant with an rgpF deletion showed the LOS band with the most retarded migration. On the basis of these results, we speculated that RgpA, RgpB, and RgpF, in that order, function in rhamnan polymerization.


2002 ◽  
Vol 184 (7) ◽  
pp. 1932-1939 ◽  
Author(s):  
Karen C. Crasta ◽  
Kim-Lee Chua ◽  
Sumathi Subramaniam ◽  
Joachim Frey ◽  
Hilda Loh ◽  
...  

ABSTRACT Riemerella anatipestifer is responsible for exudative septicemia in ducks. The genetic determinant of the CAMP cohemolysin, cam, from a strain of R. anatipestifer was cloned and expressed in Escherichia coli. Chromosomal DNA from serotype 19 strain 30/90 was used to construct a gene library in pBluescript II SK(−) vector in E. coli XL-1-Blue strain. The clones containing recombinant plasmids were screened for the CAMP reaction with Staphylococcus aureus. Those that showed cohemolysis were chosen for further analysis by sequencing. One of these clones, JFRA8, was subcloned to identify the smallest possible DNA fragment containing the CAMP cohemolysin determinant, which was located on a 3,566-bp BamHI-BstXI fragment which specified a 1,026-bp open reading frame. Clones containing recombinant plasmids carrying cam obtained by PCR cloning into E. coli M15 strain secreted an active CAMP cohemolysin. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western blot analyses confirmed that the recombinant strain expressed a protein with a molecular mass of 37 kDa and that strains from serotypes 1, 2, 3, 5, 6, and 19 expressed the cohemolysin. The deduced amino acid sequence showed high homology to those of O-sialoglycoprotein endopeptidases. Hydrolysis of radioiodinated glycophorin A confirmed that Cam is a sialoglycoprotease.


2010 ◽  
Vol 192 (9) ◽  
pp. 2407-2413 ◽  
Author(s):  
Jacalyn M. Green ◽  
Ryan Hollandsworth ◽  
Lenore Pitstick ◽  
Eric L. Carter

ABSTRACT The abg locus of the Escherichia coli chromosome includes three genes encoding proteins (AbgA, AbgB, and AbgT) that enable uptake and utilization of the folate breakdown product, p-aminobenzoyl-glutamate (PABA-GLU). We report on the purification and characterization of the p-aminobenzoyl-glutamate hydrolase (PGH) holoenzyme encoded by abgA and abgB. One-step purification was accomplished using a plasmid carrying abgAB with a hexahistidine tag on the carboxyl terminus of AbgB and subsequent metal affinity chromatography (MAC). Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed two subunits (∼53-kDa and ∼47-kDa proteins) of the expected masses of AbgB and AbgA; N-terminal sequencing confirmed the subunit identification, and amino acid analysis yielded a 1:1 ratio of the subunits. Size exclusion chromatography coupled with light-scattering analysis of purified PGH revealed a predominant molecular mass of 206 kDa and a minor component of 400 to 500 kDa. Both peaks contained PGH activity, and SDS-PAGE revealed that fractions containing activity were composed of both AbgA and AbgB. MAC-purified PGH was highly stimulated by manganese chloride. Kinetic analysis of MAC-purified PGH revealed a Km value for PABA-GLU of 60 ± 0.08 μM and a specific activity of 63,300 ± 600 nmol min−1 mg−1. Folic acid and a variety of dipeptides served as poor substrates of PGH. This locus of the E. coli chromosome may encode a portion of a folate catabolism pathway.


1991 ◽  
Vol 69 (8) ◽  
pp. 523-530 ◽  
Author(s):  
Ravi K. Chopra ◽  
Tassos P. Anastassiades ◽  
David Lohnes ◽  
Glenville Jones

Following incubation of UMR-106 cells for 48 h in the presence of [3H]glucosamine and [35S]sulfate, the newly synthesized anionic glycoconjugates were isolated from the culture medium by cetylpyridinium chloride/ethanol precipitation and further separated by DEAE-Sephacel chromatography into two radiolabelled fractions, a major component, UM I, and a minor component, UM II. UM I appeared to be homogeneous as shown by Sepharose CL-4B chromatography under dissociative conditions, and SDS-polyacrylamide gel electrophoresis. It showed a molecular mass of approximately 93 kDa on 4–15% gels. UM I was partially degraded by brief treatment with trypsin, releasing a small, terminal peptide that contained 47.6% of 35S but no 3H. Treatment of UM I with neuraminidase and 0.1 N H2SO4 (1 h at 80 °C), respectively, released 27% 3H and 38.4% 3H plus 41% 35S, suggesting the presence of a significant number of sialic acid residues, as shown by Sephadex G-50 chromatography of the digests. Amino acid analysis showed that the UM I glycoconjugate was rich in acidic amino acids (12.6% aspartic acid and 21.2% glutamic acid residues) and its N-terminal sequence was Phe-Ser-Met-Lys-Asn-Phe-, which is identical to the published N-terminal amino acid sequence of rat bone sialoprotein II. Keratanase treatment of UM I released 26% of the incorporated radioactivity, suggesting the presence of keratan sulfate chains. UM II contained a chondroitinase ABC-sensitive proteoglycan.Key words: UMR-106 cells, anionic glycoconjugates, bone sialoprotein II.


2011 ◽  
Vol 60 (4) ◽  
pp. 293-301 ◽  
Author(s):  
ADRIAN WIATER ◽  
MONIKA JANCZAREK ◽  
MAŁGORZATA PLESZCZYŃSKA ◽  
JANUSZ SZCZODRAK

alpha-1,3-Glucanases (mutanases) are currently of great interest due to their potential use in the field of dental care. These enzymes have been reported in several bacteria, yeasts and fungi, but up to now, characterization of this family of proteins has been relatively poor. In this study, we identify and characterize a mutanase gene from Trichoderma harzianum CCM F-340. Sequence analysis, on the nucleotide and amino acid levels reveals that this alpha-1,3-glucanase is highly homologous to alpha-1,3-glucanases from T harzianum isolate CBS 243.71 and T asperellum CECT 20539. T. harzianum CCM F-340 mutanase is a 634-aa residue protein with a calculated molecular mass of 67.65 kDa, composed of two distinct, highly conserved domains (a long N-terminal catalytic domain and a short C-terminal polysaccharide-binding domain) separated by a less conserved Pro-Ser-Thr-rich linker region. The mutanase gene was expressed in an E. coli BL21 (DE3) host, under the transcriptional control of T7 promoter. The purified enzyme migrated as a band of about 68 kDa after SDS-polyacrylamide gel electrophoresis, which coincided with the predicted size based on the amino acid sequence. Our data indicate that this e


1980 ◽  
Vol 187 (3) ◽  
pp. 767-774 ◽  
Author(s):  
J K Wright ◽  
J Tschopp ◽  
J C Jaton

Pure dimers, trimers, tetramers and pentamers of rabbit non-immune IgG (immunoglobulin G) or antibody IgG were prepared by polymerization in the presence of the bifunctional cross-linking reagent dithiobis (succinimidylpropionate). Oligomerization was performed either in the presence of polysaccharide antigen and specific monomeric antibody (method A) or by random cross-linking of non-immune rabbit IgG in the absence of antigen (method B). By repeated gel-filtration chromatography, samples prepared by both methods exhibited a single band in analytical sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The electrophoretic mobilities of samples prepared by method A were slightly greater than those for the corresponding samples prepared by method B. This might suggest a role played by antigen in the orientation of IgG molecules within the clusters, which may be more compact than those formed by random cross-linking. The average numbers of cross-linker molecules per oligomer varied between 3 and 6 for clusters made by method A and between 1 and 3 for clusters made by method B. Ultracentrifugal analyses of the oligomers yielded sedimentation coefficients (S20,w) of 9.6S for the dimer, 11.2S for the trimer, 13.6S for the tetramer and 16.1S for the pentamer. Comparison of the observed sedimentation coefficients with those predicted by various hydrodynamic models suggested these oligomers possessed open and linear structures. Reduction of the cross-linking molecules converted oligomers into monomeric species of IgG. C.d. spectra of some oligomers studied in the range 200-250 nm were essentially the same as that of monomeric IgG molecules, thus strongly suggesting no major conformation changes in IgG molecules within clusters. These oligomers were found to be stable for up to 2 months when stored at −70 degrees C.


Author(s):  
J. P. Petrali ◽  
E. J. Donati ◽  
L. A. Sternberger

Specific contrast is conferred to subcellular antigen by applying purified antibodies, exhaustively labeled with uranium under immunospecific protection, to ultrathin sections. Use of Seligman’s principle of bridging osmium to metal via thiocarbohydrazide (TCH) intensifies specific contrast. Ultrathin sections of osmium-fixed materials were stained on the grid by application of 1) thiosemicarbazide (TSC), 2) unlabeled specific antiserum, 3) uranium-labeled anti-antibody and 4) TCH followed by reosmication. Antigens to be localized consisted of vaccinia antigen in infected HeLa cells, lysozyme in monocytes of patients with monocytic or monomyelocytic leukemia, and fibrinogen in the platelets of these leukemic patients. Control sections were stained with non-specific antiserum (E. coli).In the vaccinia-HeLa system, antigen was localized from 1 to 3 hours following infection, and was confined to degrading virus, the inner walls of numerous organelles, and other structures in cytoplasmic foci. Surrounding architecture and cellular mitochondria were unstained. 8 to 14 hours after infection, antigen was localized on the outer walls of the viral progeny, on cytoplasmic membranes, and free in the cytoplasm. Staining of endoplasmic reticulum was intense and focal early, and weak and diffuse late in infection.


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