title: Primary structure of the peptidoglycan from the unicellular cyanobacterium Synechocystis sp. strain PCC 6714.
abstract: A peptidoglycan fraction free of non-peptidoglycan components was isolated from the unicellular cyanobacterium Synechocystis sp. strain PCC 6714. Hydrofluoric acid treatment (48%, 0 degrees C, 48 h) cleaved off from the peptidoglycan non-peptidoglycan glucosamine, mannosamine, and mannose. The purified peptidoglycan consists of N-acetyl muramic acid, N-acetyl glucosamine, L-alanine, D-alanine, D-glutamic acid, and meso-diaminopimelic acid in approximately equimolar amounts. At least partial amidation of carboxy groups in the peptide subunits is indicated. Peptide analyses and 2,4-dinitrophenyl studies of partial acid hydrolysates revealed the structure of the Synechocystis sp. strain PCC 6714 peptidoglycan to belong to the A1 gamma type (direct cross-linkage) of peptidoglycan classification. The degree of cross-linkage is about 56% and thus is in the range of that found in gram-positive bacteria. Some of the peptide units are present as tripeptides lacking the carboxy-terminal D-alanine.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000458:Cyanobacteria / Q000032:analysis*; D005971:Glutamates / Q000032:analysis; D018698:Glutamic Acid; D010455:Peptides / Q000032:analysis; D010457:Peptidoglycan / Q000032:analysis*; D013237:Stereoisomerism
chemical_list: D000596:Amino Acids; D005971:Glutamates; D010455:Peptides; D010457:Peptidoglycan; D018698:Glutamic Acid