Cloned (Comment) | Organism |
---|---|
gene PARN, recombinant expression of His-tagged enzyme in Escherichia coli strain BL21(DE3) | Homo sapiens |
Protein Variants | Comment | Organism |
---|---|---|
H449A | site-directed mutagenesis, the mutant shows loss of the negative cooperativity between the PARN dimer subunits that is evident for the m7GpppG and m7GTP binding by the wild-type protein | Homo sapiens |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
additional information | - |
additional information | model of cooperative ligand binding by PARN dimer, binding kinetics, dissociation constants, and thermodynamics, detailed overview | Homo sapiens |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
152400 | - |
recombinant His-tagged enzyme | Homo sapiens |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Homo sapiens | O95453 | - |
- |
Purification (Comment) | Organism |
---|---|
recombinant His-tagged enzyme from Escherichia coli strain BL21(DE3) by metal affinity chromatography | Homo sapiens |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
additional information | molecular mechanism of 5' cap recognition by PARN, overview. The PARN cap-binding site is bipartite: Trp475 constitutes the essential binding surface for m7G, while the first transcribed nucleoside is bound by the nuclease domain. The enzyme interacts with m7GpppG, m7Gpppm2'OG, m7GTP, GpppG(macro), GpppG(micro), m2_2.7GTP, and m3_2.2.7GTP. Role of His449 in mRNA 5' cap binding, involvement of His449 in sustaining the proper specificity of the enzyme, overview | Homo sapiens | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
dimer | secondary structure content predictions for full-length PARN | Homo sapiens |
Synonyms | Comment | Organism |
---|---|---|
PARN | - |
Homo sapiens |
General Information | Comment | Organism |
---|---|---|
additional information | poly(A)-specific ribonuclease (PARN) is a dimeric exoribonuclease that efficiently degrades mRNA 3' poly(A) tails while also simultaneously interacting with the mRNA 5' cap. The mRNA 5' cap structure plays a pivotal role in coordination of eukaryotic translation and mRNA degradation. Molecular recognition of mRNA 5' cap by 3' poly(A)-specific ribonuclease (PARN) differs from interactions known for other cap-binding proteins: 1. the auxiliary biological function of 5' cap binding by the 3' degrading enzyme is accomplished by negative cooperativity of PARN dimer subunits, 2. non-coulombic interactions are major factors in the complex formation, and 3. PARN has versatile activity toward alternative forms of the cap. These characteristics contribute to stabilization of the PARN-cap complex needed for the deadenylation processivity. Fluorescence and NMR spectroscopic analysis. Model of cooperative ligand binding by PARN dimer. Enzyme-ligand (cap and cap analogues) interaction analysis by surface plasmon resonance, local conformational changes of PARN upon 5' mRNA cap binding, small increase in the beta-strand and coil contributions and complex formation in the vicinity of the residues Trp475 and Asp478. PARN seems to recognize the 5' cap in a simple fashion by virtue of the single-sided stacking that is unique among cap-binding proteins | Homo sapiens |