PDBsum entry 3nk6

Transferase

PDB id: 3nk6

Contents

Protein chains

264 a.a. *

Waters ×312

* Residue conservation analysis

PDB id:

3nk6

Name:

Transferase

Title:

Structure of the nosiheptide-resistance methyltransferase

Structure:

23s rrna methyltransferase. Chain: a, b. Synonym: rrna (adenosine-2'-o-)-methyltransferase, 23s rrna methylase. Engineered: yes

Source:

Streptomyces actuosus. Organism_taxid: 1885. Gene: nsr. Expressed in: escherichia coli. Expression_system_taxid: 469008.

Resolution:

2.00Å R-factor: 0.204 R-free: 0.254

Authors:

H.Yang,Z.Wang,Y.Shen,P.Wang,A.Murchie,Y.Xu

Key ref:

H.Yang et al. (2010). Crystal structure of the nosiheptide-resistance methyltransferase of Streptomyces actuosus. Biochemistry, 49, 6440-6450. PubMed id: 20550164

Date:

18-Jun-10 Release date: 21-Jul-10

Protein chains

P52391  (NSHR_STRAS) -  23S rRNA (adenosine(1067)-2'-O)-methyltransferase from Streptomyces actuosus

Seq: 274 a.a.

Struc: 264 a.a.

Enzyme reactions

• Enzyme class: E.C.2.1.1.230 - 23S rRNA (adenosine(1067)-2'-O)-methyltransferase.
• Reaction: adenosine₁₀₆₇ in 23S rRNA + S-adenosyl-L-methionine = 2'-O- methyladenosine₁₀₆₇ in 23S rRNA + S-adenosyl-L-homocysteine + H⁺

Molecule diagrams generated from .mol files obtained from the KEGG ftp site

Added reference

Biochemistry 49:6440-6450 (2010)

PubMed id: 20550164

Crystal structure of the nosiheptide-resistance methyltransferase of Streptomyces actuosus.

H.Yang, Z.Wang, Y.Shen, P.Wang, X.Jia, L.Zhao, P.Zhou, R.Gong, Z.Li, Y.Yang, D.Chen, A.I.Murchie, Y.Xu.

ABSTRACT

Nosiheptide-resistance methyltransferase (NHR) of Streptomyces actuosus is a class IV methyltransferase of the SpoU family and methylates 23S rRNA at nucleotide Adenosine corresponding to A1067 in Escherichia Coli. Such methylation is essential for resistance against nosiheptide, a sulphur peptide antibiotic, which is produced by the nosiheptide -producing strain, Streptomyces actuosus. Here, we report the crystal structures of NHR and NHR in complex with SAM (S-adenosyl-L-methionine) at 2.0 and 2.1 A resolution, respectively. NHR forms a functional homodimer and dimerization is required for methyltransferase activity. The monomeric NHR is comprised of N-terminal RNA binding domain (NTD) and C-terminal catalytic domain (CTD). Overall, the structure of NHR suggests that the methyltransferase activity is achieved by "reading" the RNA substrate with NTD and "adding" methyl group using CTD. Comprehensive mutagenesis and methyltransferase activity assays reveal critical regions for SAM binding in CTD and loops (L1 and L3) essential for RNA recognition in NTD. Finally, the catalytic mechanism and structural model that NHR recognize 23S rRNA is proposed based on the structural and biochemical analyses. Thus, our systematic structural studies reveal the substrate recognition and modification by the nosiheptide-resistance methyltransferase.