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STRINGSTRING
STRING protein interaction network
Nodes:
Network nodes represent proteins
splice isoforms or post-translational modifications are collapsed, i.e. each node represents all the proteins produced by a single, protein-coding gene locus.
Node Color
colored nodes:
query proteins and first shell of interactors
white nodes:
second shell of interactors
Node Content
empty nodes:
proteins of unknown 3D structure
filled nodes:
some 3D structure is known or predicted
Edges:
Edges represent protein-protein associations
associations are meant to be specific and meaningful, i.e. proteins jointly contribute to a shared function; this does not necessarily mean they are physically binding to each other.
Known Interactions
from curated databases
experimentally determined
Predicted Interactions
gene neighborhood
gene fusions
gene co-occurrence
Others
textmining
co-expression
protein homology
Your Input:
Neighborhood
Gene Fusion
Cooccurence
Coexpression
Experiments
Databases
Textmining
[Homology]
Score
ppkPolyphosphate kinase, component of rna degradosome; Catalyzes the reversible transfer of the terminal phosphate of ATP to form a long-chain polyphosphate (polyP). Can form linear polymers of orthophosphate with chain lengths up to 1000 or more. Can use GTP instead of ATP, but the efficiency of GTP is 5% that of ATP. Also exhibits several other enzymatic activities, which include: ATP synthesis from polyP in the presence of excess ADP, general nucleoside- diphosphate kinase activity, linear guanosine 5'-tetraphosphate (ppppG) synthesis and autophosphorylation (688 aa)    
Predicted Functional Partners:
ppx
Exopolyphosphatase / guanosine-5'-triphosphate,3'-diphosphate pyrophosphatase; Degradation of inorganic polyphosphates (polyP). Releases orthophosphate processively from the ends of the polyP chain. Has a strong preference for long-chain polyphosphates and has only weak affinity for smaller size polyP of about 15 residues
 
  
 0.993
ppa
Inorganic pyrophosphatase; Catalyzes the hydrolysis of inorganic pyrophosphate (PPi) forming two phosphate ions
    
 0.965
gpp
Exopolyphosphatase / guanosine-5'-triphosphate,3'-diphosphate pyrophosphatase; Catalyzes the conversion of pppGpp to ppGpp. Guanosine pentaphosphate (pppGpp) is a cytoplasmic signaling molecule which together with ppGpp controls the 'stringent response', an adaptive process that allows bacteria to respond to amino acid starvation, resulting in the coordinated regulation of numerous cellular activities . In vitro, can hydrolyze pppGp . Also has exopolyphosphatase activity, catalyzing the release of orthophosphate by processive hydrolysis of the phosphoanyhydride bonds of polyphosphate c [...]
 
  
 0.878
relA
(p)ppgpp synthetase i/gtp pyrophosphokinase; In eubacteria ppGpp (guanosine 3'-diphosphate 5-' diphosphate) is a mediator of the stringent response which coordinates a variety of cellular activities in response to changes in nutritional abundance. This enzyme catalyzes the formation of pppGpp which is then hydrolyzed to form ppGpp. The second messengers ppGpp and c-di-GMP together control biofilm formation in response to translational stress; ppGpp represses biofilm formation while c-di-GMP induces it. ppGpp activates transcription of CsrA-antagonistic small RNAs CsrB and CsrC, which d [...]
   
 
 0.738
phoU
Negative regulator of phor/phob two-component regulator; Part of the phosphate (Pho) regulon, which plays a key role in phosphate homeostasis. Encoded together with proteins of the phosphate-specific transport (Pst) system in the polycistronic pstSCAB- phoU operon. PhoU is essential for the repression of the Pho regulon at high phosphate conditions. In this role, it may bind, possibly as a chaperone, to PhoR, PhoB or a PhoR-PhoB complex to promote dephosphorylation of phospho-PhoB, or inhibit formation of the PhoR- PhoB transitory complex. Is also part of complex networks important for [...]
     
 0.724
lon
Dna-binding atp-dependent protease la; ATP-dependent serine protease that mediates the selective degradation of mutant and abnormal proteins as well as certain short- lived regulatory proteins, including some antitoxins. Required for cellular homeostasis and for survival from DNA damage and developmental changes induced by stress. Degrades polypeptides processively to yield small peptide fragments that are 5 to 10 amino acids long. Binds to DNA in a double-stranded, site-specific manner. Endogenous substrates include the regulatory proteins RcsA and SulA, the transcriptional activator [...]
      
 0.704
phoB
Two-component system, ompr family, phosphate regulon response regulator phob; This protein is a positive regulator for the phosphate regulon. Transcription of this operon is positively regulated by PhoB and PhoR when phosphate is limited
 
   
 0.686
pstS
Phosphate abc transporter periplasmic binding protein; Part of the ABC transporter complex PstSACB involved in phosphate import
     
 0.637
pstA
Phosphate abc transporter membrane subunit psta; Part of the binding-protein-dependent transport system for phosphate; probably responsible for the translocation of the substrate across the membrane
     
 0.633
phoR
Two-component system, ompr family, phosphate regulon sensor histidine kinase phor; Member of the two-component regulatory system PhoR/PhoB involved in the phosphate regulon genes expression. PhoR may function as a membrane-associated protein kinase that phosphorylates PhoB in response to environmental signals
     
 0.630
Your Current Organism:
Escherichia coli K12 MG1655
NCBI taxonomy Id: 511145
Other names: E. coli str. K-12 substr. MG1655, Escherichia coli K12 substr. MG1655, Escherichia coli MG1655, Escherichia coli str. K-12 substr. MG1655, Escherichia coli str. K12 substr. MG1655, Escherichia coli str. MG1655, Escherichia coli strain MG1655
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