title: Characterization and cDNA cloning of two glycine- and histidine-rich antimicrobial peptides from the roots of shepherd's purse, Capsella bursa-pastoris.
abstract: Two novel antimicrobial peptides were isolated and characterized from the roots of shepherd's purse, Capsella bursa-pastoris. These antimicrobial peptides, named shepherin I and shepherin II, consist of 28 and 38 amino acids, respectively, and are glycine- and histidine-rich peptides. Shepherin I and shepherin II have 67.9% and 65.8% (mol/mol) glycine, respectively, and 28.6% and 21.1% (mol/mol) histidine, respectively. Both shepherins have a Gly-Gly-His motif. These antimicrobial peptides exhibit antimicrobial activity against Gram-negative bacteria and fungi. Circular dichroism spectra of shepherin I and shepherin II showed that shepherin I and shepherin II in 50% trifluoroethanol have 66.7% and 75% random coils, respectively, without any alpha-helices. cDNA sequence analysis revealed that shepherin I and shepherin II are produced from a single polypeptide, designated shep-GRP, consisting of 120 amino acids; shep-GRP has five distinct domains, an amino-terminal putative signal peptide, a shepherin I, a linker dipeptide, a shepherin II and a carboxy-terminal peptide. Southern blot analysis indicates that the gene encoding shepherins belongs to a low-complexity gene family. Northern blot analysis revealed that transcripts of shep-GRP are present in roots but not in leaves and stems.
authors: Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Yusong-gu, Taejon.
authors: C J
authors: CJ
authors: Park
authors: C B
authors: CB
authors: Park
authors: S S
authors: SS
authors: Hong
authors: H S
authors: HS
authors: Lee
authors: S Y
authors: SY
authors: Lee
authors: S C
authors: SC
authors: Kim
mesh_terms: D000595:Amino Acid Sequence; D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D001419:Bacteria / Q000187:drug effects / Q000254:growth & development; D001483:Base Sequence; D015152:Blotting, Northern; D015139:Blotting, Southern; D019607:Brassicaceae / Q000235:genetics*; D002455:Cell Division / Q000187:drug effects; D002942:Circular Dichroism; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics*; D018744:DNA, Plant / Q000235:genetics; D005658:Fungi / Q000187:drug effects / Q000254:growth & development; D018506:Gene Expression Regulation, Plant; D005998:Glycine / Q000235:genetics; D006639:Histidine / Q000235:genetics; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D010455:Peptides; D010940:Plant Proteins / Q000235:genetics* / Q000494:pharmacology; D018517:Plant Roots / Q000235:genetics*; D020033:Protein Isoforms / Q000235:genetics / Q000494:pharmacology; D018749:RNA, Plant / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein; D017386:Sequence Homology, Amino Acid; D014018:Tissue Distribution
chemical_list: D000900:Anti-Bacterial Agents; D018076:DNA, Complementary; D018744:DNA, Plant; C417582:GRP protein, Capsella bursa-pastoris; D010455:Peptides; D010940:Plant Proteins; D020033:Protein Isoforms; D018749:RNA, Plant; D006639:Histidine; D005998:Glycine