GUANOSINE PENTAPHOSPHATE PHOSPHOHYDROLASE OF ESCHERICHIA-COLI IS A LONG-CHAIN EXOPOLYPHOSPHATASE

被引:124
作者
KEASLING, JD
BERTSCH, L
KORNBERG, A
机构
[1] STANFORD UNIV,MED CTR,SCH MED,DEPT BIOCHEM,STANFORD,CA 94305
[2] UNIV CALIF BERKELEY,DEPT CHEM ENGN,BERKELEY,CA 94720
关键词
D O I
10.1073/pnas.90.15.7029
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
An exopolyphosphatase [exopoly(P)ase; EC 3.6.1.11] activity has recently been purified to homogeneity from a mutant strain of Escherichia coli which lacks the principal exopoly(P)ase. The second exopoly(P)ase has now been identified as guanosine pentaphosphate phosphohydrolase (GPP; EC 3.6.1.40) by three lines of evidence: (i) the sequences of five tryptic digestion fragments of the purified protein are found in the translated gppA gene, (ii) the size of the protein (100 kDa) agrees with published values for GPP, and (iii) the ratio of exopoly(P)ase activity to GPP activity remains constant throughout a 300-fold purification in the last steps of the procedure. The enzyme liberates orthophosphate by processive hydrolysis of the phosphoanhydride bonds of polyphosphate [poly(P)] chains (1000 residues) or by hydrolysis of the 5'-gamma-phosphate of guanosine 5'-triphosphate 3'-diphosphate (pppGpp) to guanosine 5'-diphosphate 3'-diphosphate (ppGpp or ''magic spot''). The K(m) for long-chain poly(P) as a substrate (almost-equal-to 0.5 nM) is far lower than that for pppGpp (0.13 mM); the k(cat) for the poly(P)ase activity is 1.1 s-1 and that for pppGpp hydrolase is 0.023 s-1. These and other findings direct attention to possible functions of poly(P) in the response of E. coli to stresses and deprivations.
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页码:7029 / 7033
页数:5
相关论文
共 20 条
[1]  
AHN KH, 1990, J BIOL CHEM, V265, P11734
[2]  
AKIYAMA M, 1993, J BIOL CHEM, V268, P633
[3]  
AKIYAMA M, 1992, J BIOL CHEM, V267, P22556
[4]   INVESTIGATIONS OF THE STATE OF THE MANGANESE IN LACTOBACILLUS PLANTARUM [J].
ARCHIBALD, FS ;
FRIDOVICH, I .
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS, 1982, 215 (02) :589-596
[5]   PREPARATION OF GUANOSINE TETRAPHOSPHATE (PPGPP) AND GUANOSINE PENTAPHOSPHATE (PPPGPP) FROM ESCHERICHIA-COLI RIBOSOMES [J].
CASHEL, M .
ANALYTICAL BIOCHEMISTRY, 1974, 57 (01) :100-107
[6]  
Cashel M., 1987, CELL MOL BIOL, P1410
[7]   ISOLATION OF INTACT CHAINS OF POLYPHOSPHATE FROM PROPIONIBACTERIUM-SHERMANII GROWN ON GLUCOSE OR LACTATE [J].
CLARK, JE ;
BEEGEN, H ;
WOOD, HG .
JOURNAL OF BACTERIOLOGY, 1986, 168 (03) :1212-1219
[8]   SEQUESTRATION OF ARGININE BY POLYPHOSPHATE IN VACUOLES OF YEAST (SACCHAROMYCES-CEREVISIAE) [J].
DURR, M ;
URECH, K ;
BOLLER, T ;
WIEMKEN, A ;
SCHWENCKE, J ;
NAGY, M .
ARCHIVES OF MICROBIOLOGY, 1979, 121 (02) :169-175
[9]  
HARA A, 1983, J BIOL CHEM, V258, P1678
[10]   MSI AND MSII MADE ON RIBOSOME IN IDLING STEP OF PROTEIN-SYNTHESIS [J].
HASELTIN.WA ;
BLOCK, R ;
WEBER, K ;
GILBERT, W .
NATURE, 1972, 238 (5364) :381-+