Sunday, August 1, 2010

3 D MaCroMolecULe

Spatial structure of Lch-beta peptide from two-component lantibiotic Lichenicidin VK21

PRIMARY CITATION

Isolation, structure elucidation, and synergistic antibacterial activity of a novel two-component lantibiotic lichenicidin from Bacillus licheniformis VK21.

Journal: (2010) Biochemistry

http://www.pdb.org/pdb/explore/explore.do?structureId=2KTO

PubMed: 20578714

DOI: 10.1021/bi100871b

PubMed Abstract:

A novel synergetic lantibiotic pair, Lchalpha(3249.51 Da) and Lchbeta(3019.36 Da), termed lichenicidin VK21, was isolated from the producer strain Bacillus licheniformis VK21. Chemical and spatial structures of Lchalphaand Lchbeta were determined. Each peptide contains 31 amino acid residues linked by 4 intramolecular thioether bridges and the N-terminal 2-oxobutyryl group. Spatial structures of Lchalpha and Lchbetawere studied by NMR spectroscopy in methanol solution. Lchalpha peptide displays structural homology with mersacidin-like lantibiotics and involves relatively well-structured N- and C-terminal domains connected by a flexible loop stabilized by thioether bridge Ala11-S-Ala21. In contrast, the Lchbetapeptide represents prolonged hydrophobic alpha-helix flanked with more flexible N- and C-terminal domains. A lantibiotic cluster of the Bacillus licheniformis VK21 genome which comprises the structural genes, lchA1 and lchA2, encoding the lantibiotics precursors, as well as the gene of a modifying enzyme lchM1, was amplified and sequenced. The mature peptides, Lchalphaand Lchbetainteract synergistically to possess antibiotic activity against Gram-positive bacteria within a nanomolar concentration range, though the individual peptides were shown to be active at micromolar concentrations. Our results afford molecular insight into mechanism of lichenicidin VK21 action.

RELATED STRUCTURES
Primary Citation of: 2KTN 2KTO

EXPERIMENTAL DETAILS
Method: Solution NMR
Experimental Data: NMR Restraint Grid



MOLECULAR DESCRIPTION
Classification: Antibiotic
Structure Weight:
3031.56

Molecule:
LchB

Polymer:
1

Type:
polypeptide (L)

Lenght: 32
Chains: A

SOURCE
Polymer: 1
Scientific Name:
Bacillus Licheniformis


RELATED PDB ENTRIES

2ktn: structure of alpha peptide

MODIFIED RESIDUES

Identifier

Name

Formula

Parent

type

2KT

2-KETOBUTYRIC ACID

C4 H6 O3


nonPolymer

DBU

(2E)-2-AMINOBUT-2-ENOIC ACID

C4 H7 N O2

ALA

glycine

DAL

D-ALANINE

C3 H7 N O2


dPeptideLinking

DBA

2-AMINO-ACRYLIC ACID

C3 H5 N O2

ALA

glycine

DHB

D-ALPHA-AMINOBUTYRIC ACID

C4 H9 N O2


dpeptideLinking

















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