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:
a 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
Cooccurrence
Coexpression
Experiments
Databases
Textmining
[Homology]
Score
ppxExopolyphosphatase; 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. (513 aa)    
Predicted Functional Partners:
ppk
Polyphosphate 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.
  
 0.998
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 [...]
   
 
 0.962
gpp
Guanosine pentaphosphatase/exopolyphosphatase; 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 chains (1000 residues).
  
 
0.925
spoT
Bifunctional (p)ppGpp synthetase II/ guanosine-3',5'-bis pyrophosphate 3'-pyrophosphohydrolase; 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 both the synthesis and degradation of 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 s [...]
   
 
 0.910
purN
Phosphoribosylglycinamide formyltransferase 1; Catalyzes the transfer of a formyl group from 10- formyltetrahydrofolate to 5-phospho-ribosyl-glycinamide (GAR), producing 5-phospho-ribosyl-N-formylglycinamide (FGAR) and tetrahydrofolate; Belongs to the GART family.
 
    0.752
purM
Phosphoribosylaminoimidazole synthetase = AIR synthetase; Protein involved in purine nucleotide biosynthetic process; Belongs to the AIR synthase family.
 
    0.671
ppa
Inorganic pyrophosphatase; Catalyzes the hydrolysis of inorganic pyrophosphate (PPi) forming two phosphate ions.
     
 0.670
tehB
Tellurite, selenium methyltransferase, SAM-dependent; S-adenosyl-L-methionine dependent methyltransferase that catalyzes the methylation of tellurite and is responsible for tellurite resistance when present in high copy number. Can also methylate selenite and selenium dioxide. Is thus able to detoxify different chalcogens. Cannot methylate arsenic compounds. Belongs to the TehB family.
 
      0.581
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 [...]
     
 0.564
pitB
Phosphate transporter; Low-affinity inorganic phosphate transport; Belongs to the inorganic phosphate transporter (PiT) (TC 2.A.20) family. Pit subfamily.
     
 0.563
Your Current Organism:
Escherichia coli K12
NCBI taxonomy Id: 511145
Other names: E. coli str. K-12 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
Server load: low (22%) [HD]
STRING is a Core Data Resource as designated by Global Biodata Coalition and ELIXIR.