title: Sequence and structural relationships of leucocins A-, B- and C-TA33a from Leuconostoc mesenteroides TA33a.
abstract: Amino acid sequences of two of the three bacteriocins from Leuconostoc mesenteroides TA33a were determined and their sequence-structure relationships investigated. Leucocin B-TA33a consists of 31 amino acid residues, with a molecular mass of 3466 Da. Leucocin B-TA33a does not belong to the pediocin family of bacteriocins, but shares 62% homology with mesenterocin 52B. A partial sequence of 36 amino acids of leucocin C-TA33a (4598 Da) was determined. Leucocin C-TA33a belongs to the class II bacteriocins having the consensus YGNGV motif. The third bacteriocin, leucocin A-TA33a, is identical to leucocin A-UAL 187. Circular dichroism spectra of the leucocins in aqueous solution and micellar SDS indicated that they undergo a structural transition when in a membrane-mimicking environment. Theoretical predictions from circular dichroism data suggest that leucocins A-, B- and C-TA33a adopt a beta-structure (48%) in membrane-mimicking environments. Sequence alignments and secondary structure predictions for the N-terminus of leucocins A- and C-TA33a predicted that Cys-9 and Cys-14 are connected by a disulfide bridge and form two beta-strands.
authors.affiliation: Department of Genetics, University of Natal, Pietermaritzburg, Private Bag X01, Scottsville, 3209, South Africa.|Department of Microbiology, University of the Witwatersrand, Private Bag 3, WITS, 2050, South Africa.
authors.forename: Maria A
authors.initials: MA
authors.lastname: Papathanasopoulos
authors.affiliation: Department of Genetics, University of Natal, Pietermaritzburg, Private Bag X01, Scottsville, 3209, South Africa.
authors.forename: Gary A
authors.initials: GA
authors.lastname: Dykes
authors.affiliation: Laboratoire de Fermentations et de Bioconversions Industrielles, ENSAIA, Vandoeuvre les Nancy, France.
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Revol-Junelles
authors.affiliation: IBMIG, Laboratoire de Biochimie des Proteines, Université de Poitiers, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Delfour
authors.affiliation: Department of Microbiology, University of the Witwatersrand, Private Bag 3, WITS, 2050, South Africa.
authors.forename: Alexander
authors.initials: A
authors.lastname: von Holy
authors.affiliation: Department of Genetics, University of Natal, Pietermaritzburg, Private Bag X01, Scottsville, 3209, South Africa.
authors.forename: John W
authors.initials: JW
authors.lastname: Hastings
mesh_terms: D000595:Amino Acid Sequence; D001430:Bacteriocins / Q000737:chemistry* / Q000302:isolation & purification; D002942:Circular Dichroism; D007934:Leuconostoc / Q000737:chemistry*; D013058:Mass Spectrometry; D008969:Molecular Sequence Data; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D016415:Sequence Alignment; D017421:Sequence Analysis
chemical_list: D001430:Bacteriocins; C071726:leucocin A-UAL 187