Comparison of Base Specificity and Other Enzymatic Properties of Two Protozoan Ribonucleases from<i>Physarum polycephalum</i>and<i>Dictyostelium discoideum</i>

Inokuchi, Norio; Saitoh, Shigeru; Kobayashi, Hiroko; Itagaki, Tadashi; Koyama, Takashi; Uchiyama, Saburo; Irie, Masachika

doi:10.1271/bbb.63.141

Cited by 8 publications

(11 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…34) The definition of the subsite of RNase Os is that proposed by Richards and Wycoff. 37) B1 and B2 sites are base recognition sites corresponding to base X and Y of dinucleosidephosphate substrate (XpY). The parameter ÍNpG is the sum of initial velocities of GpG, ApG, CpG and UpG.…”

Section: Discussionmentioning

confidence: 99%

“…37) The base specificity of both sites could be estimated from the initial rates of hydrolysis of 16 dinucleoside phosphates as described. 37) That is, the comparison of the sum of v 0 values of GpYs, ApYs, CpYs and UpYs for an enzyme may have some correlation to the frequency of cleavage on the 3Ј-side of a given base in RNA hydrolysis (B1 site specificity), assuming the random distribution of four bases in RNA. Similarly, the sum of v 0 values of XpGs, XpAs, XpCs and XpUs may have correlated to those of the cleavage site on the 5Ј-side of a given base (B2 site specificity).…”

Section: Expression Of Rnase Os From Yeastmentioning

confidence: 99%

“…Similarly, the sum of v 0 values of XpGs, XpAs, XpCs and XpUs may have correlated to those of the cleavage site on the 5Ј-side of a given base (B2 site specificity). 37) This kind of analysis was applied to RNase Os. The results are summarized in Table 5.…”

Section: Expression Of Rnase Os From Yeastmentioning

confidence: 99%

See 2 more Smart Citations

Amino Acid Sequence and Characterization of a Rice Bran Ribonuclease

Iwama

Ogawa

Yamagishi

et al. 2001

Biological & Pharmaceutical Bulletin

Self Cite

View full text Add to dashboard Cite

RNase T2 family enzymes which are base non-specific and have a molecular mass of about 24 kDa, distributed widely from viruses to microbes, plants and animals. 1)They share two well conserved active site sequences, CAS I and CAS II. Therefore, they are a good model with which to study the evolution of RNases. In the plant kingdom, members of the RNase T2 family are classified into two classes, S-RNases which are the products of S-genes and function as self-incompatibility factors, 2) and S-like RNases.3) The latter enzymes are known to be induced by phosphate deprivation [Jost et al.,4) Bariola et al. 5)], in the case of senescence [Lers et al. 6) ], and exist in the seeds probably for defense [Ide et al.,7) Rojo et al. 8,9) ]. In terms of the evolutional change of plant RNases, knowledge is limited to those plants belonging to Dicotyledoneae, except for barley. 10) These include several plants of Solanaceae [tomato,4,11) and tobacco, 3,12) petunia 13) and a kind of potato 14) ], Cucurbitaceae [bitter gourd, 7) cucumber, 18) and others. In this report, we will describe the amino acid sequence of an RNase from rice bran (Oryza sativa) which is a member of Monocotyledoneae, and its enzymatic properties. MATERIALS AND METHODSEnzymes Lysylendopeptidase and g-pyroglutamine aminopeptidase were obtained from Wako Pure Chemical Ind., Ltd. (Osaka, Japan) and Calbiochem-Novabiochem. Co., Ltd., (LaJolla, LA, U.S.A.), respectively.Other Reagents Yeast RNA was a product of Marin Bio (Tokyo, Japan). Sixteen dinucleoside phosphates were purchased from Sigma (St. Louis, MO, U.S.A.). Phospho-cellulose and DE-52 were obtained from Whatman (Clifton, NJ, U.S.A.). A Mono Q column was obtained from Amersham Pharmcia Biotech (Buckinghamshire, England).Enzyme Assay (i) RNA as substrate: RNase assay was carried out as described 19) with RNA as substrate at pH 5.5 and 37°C. (ii) Dinucleosidephosphates as substrate: The rates of hydrolysis of 16 dinucleoside phosphates (XpYs), where X and Y were one of A, G, C and U, were measured spectrophotometrically as described by Imazawa et al. 20) in 0.1 M sodium acetate buffer (pH 5.5) at 22°C.Protein Concentration The protein concentration was measured spectrophotometrically assuming the absorbancy at 280 nm of a 0.1% protein solution to be 1.0.Purification of an RNase from Rice Bran Purification of an RNase from rice bran was performed by modification of the procedure reported by Yokoyama et al. 21)Step 1. Four kilograms of rice bran (product from a strain of Oryza sativa, Koshihikari) was suspended in 12 l of 20 mM sodium phosphate buffer (pH 7.0) and extracted by vigorous stirring at 4°C. The extract was filtered through a layer of cotton sheet, and the filtrate was centrifuged at 10000 rpm for 10 min. The pH of the supernatant was adjusted to 5.0 by addition of dil. HCl. The supernatant was kept at 4°C overnight, and the precipitate formed was eliminated by centrifugation at 10000 rpm for 10 min (crude extract).Step 2. The crude extract was fractionated by ammonium sulfate, and the pr...

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Expression Of Rnase Os From Yeastmentioning

confidence: 99%

See 1 more Smart Citation

Amino Acid Sequence and Characterization of a Rice Bran Ribonuclease

Iwama

Ogawa

Yamagishi

et al. 2001

Biological & Pharmaceutical Bulletin

Self Cite

View full text Add to dashboard Cite

show abstract

“…21,22) The base specificity of both sub-sites were estimated from the initial rates of hydrolysis of 16 dinucleoside phosphates or V max =K m values, as described previously. 21,22) A comparison of the sum of v 0 values of GpYs, ApYs, CpYs, and UpYs for an enzyme might have some correlation to the frequency of cleavage on the 3 0 -side of a given base in RNA hydrolysis (B1 site specificity), assuming a random distribution of the four bases in RNA. Similarly, the sum of v 0 values of XpGs, XpAs, XpCs, and XpUs might have some correlation to those of the cleavage site on the 5 0 -side of a given base in RNA hydrolysis (B2 site specificity).…”

Section: Base Specificity Of Rnase Ok2mentioning

confidence: 99%

“…22) B1 and B2 sites correspond to base X and Y of the dinucleosidephosphate substrate (XpY). The parameter AEN 0 pG is the sum of initial velocities of GpG, ApG, CpG, and UpG.…”

Section: Expression Of Rnase Ok2 From Yeast and Escherichia Colimentioning

confidence: 99%

On a Salmon (Onchorhynchus keta) Liver RNase, Belonging to RNase T2 Family: Primary Structure and Some Properties

Suzuki

Kanno

Ogawa

et al. 2005

Bioscience, Biotechnology, and Biochemistry

Self Cite

View full text Add to dashboard Cite

Intracellular ribonuclease isozyme activity of the cellular slime mold cells,Dictyostelium discoideum Ax2 andDictyostelium mucoroides

Uchiyama

Nagai

Inokuchi

et al. 1999

J. Basic Microbiol.

Self Cite

View full text Add to dashboard Cite

The isozymes of ribonuclease were analyzed in cell‐free, crude extracts of cells by reversed activity staining of polyacrylamide gradient gels after electrophoresis. We previously reported three isozymes of the intracellular ribonuclease in Dictyostelium discoideum NC4, which were found in vegetative cells. In the present study, we examined the ribonucleolytic activity of an axenic strain of D. discoideum Ax2 cells which can grow with or without bacteria. The mobility of these isozymes (Dd I, II and III) was the same regardless of the difference in the feeding condition. We also found the three isozymes of D. mucoroides cells, Dm I, II and III. Dm I was different from Dd I in D. discoideum cells, while Dm II and Dm III were the same as Dd II and Dd III in terms of the mobility in polyacrylamide gradient gels during electrophoresis.

show abstract

Comparison of Base Specificity and Other Enzymatic Properties of Two Protozoan Ribonucleases fromPhysarum polycephalumandDictyostelium discoideum

Cited by 8 publications

References 12 publications

Amino Acid Sequence and Characterization of a Rice Bran Ribonuclease

Amino Acid Sequence and Characterization of a Rice Bran Ribonuclease

On a Salmon (Onchorhynchus keta) Liver RNase, Belonging to RNase T2 Family: Primary Structure and Some Properties

Intracellular ribonuclease isozyme activity of the cellular slime mold cells,Dictyostelium discoideum Ax2 andDictyostelium mucoroides

Contact Info

Product

Resources

About