PDBsum entry 4z0u

Hydrolase/peptide

PDB id: 4z0u

Contents

Protein chains

155 a.a.

Ligands

ASP-ILE-PRO-PHE ×2

Waters ×83

PDB id:

4z0u

Name:

Hydrolase/peptide

Title:

Rnase hi/ssb-ct complex

Structure:

Ribonuclease h. Chain: a, b. Synonym: rnase h. Engineered: yes. Ssb-ct peptide. Chain: d, e. Engineered: yes

Source:

Escherichia coli o139:h28. Organism_taxid: 331111. Strain: e24377a / etec. Gene: rnha, ece24377a_0219. Expressed in: escherichia coli. Expression_system_taxid: 562. Synthetic: yes. Escherichia coli. Organism_taxid: 562

Resolution:

2.00Å R-factor: 0.213 R-free: 0.241

Authors:

C.Petzold,J.L.Keck

Key ref:

C.Petzold et al. (2015). Interaction with Single-stranded DNA-binding Protein Stimulates Escherichia coli Ribonuclease HI Enzymatic Activity. J Biol Chem, 290, 14626-14636. PubMed id: 25903123 DOI: 10.1074/jbc.M115.655134

Date:

26-Mar-15 Release date: 29-Apr-15

Protein chains

A7ZHV1  (RNH_ECO24) -  Ribonuclease H from Escherichia coli O139:H28 (strain E24377A / ETEC)

Seq: 155 a.a.

Struc: 155 a.a.

Enzyme reactions

• Enzyme class: E.C.3.1.26.4 - ribonuclease H.
• Reaction: Endonucleolytic cleavage to 5'-phosphomonoester.

DOI no: 10.1074/jbc.M115.655134

J Biol Chem 290:14626-14636 (2015)

PubMed id: 25903123

Interaction with Single-stranded DNA-binding Protein Stimulates Escherichia coli Ribonuclease HI Enzymatic Activity.

C.Petzold, A.H.Marceau, K.H.Miller, S.Marqusee, J.L.Keck.

ABSTRACT

Single-stranded (ss) DNA-binding proteins (SSBs) bind and protect ssDNA intermediates formed during replication, recombination, and repair reactions. SSBs also directly interact with many different genome maintenance proteins to stimulate their enzymatic activities and/or mediate their proper cellular localization. We have identified an interaction formed between Escherichia coli SSB and ribonuclease HI (RNase HI), an enzyme that hydrolyzes RNA in RNA/DNA hybrids. The RNase HI·SSB complex forms by RNase HI binding the intrinsically disordered C terminus of SSB (SSB-Ct), a mode of interaction that is shared among all SSB interaction partners examined to date. Residues that comprise the SSB-Ct binding site are conserved among bacterial RNase HI enzymes, suggesting that RNase HI·SSB complexes are present in many bacterial species and that retaining the interaction is important for its cellular function. A steady-state kinetic analysis shows that interaction with SSB stimulates RNase HI activity by lowering the reaction Km. SSB or RNase HI protein variants that disrupt complex formation nullify this effect. Collectively our findings identify a direct RNase HI/SSB interaction that could play a role in targeting RNase HI activity to RNA/DNA hybrid substrates within the genome.