title: Drosophila laminin A chain sequence, interspecies comparison, and domain structure of a major carboxyl portion.
abstract: Recent studies ascribed some biological actions of cell adhesion and cell outgrowth to the carboxyl-most 1200 amino acids of vertebrate laminin A chains. Here we report a 6.1-kilobase pair nucleotide cDNA sequence encoding 1951 amino acids and the carboxyl end of a Drosophila laminin A chain. It corresponds to the mouse laminin A domains G, I, II, and III, but may represent a different type of laminin A chain. The arrangement of the cysteine-rich repeats of domain III resembles that of B2 chains. However, it has more amino acid identity with a portion of the mouse laminin A chain domain IIIb than with other laminin repeats. Domains I and II are consistent with an interrupted coiled-coil alpha-helical model of the long arm of laminin but are poorly conserved. The G domain contains five subdomains which are individually related to subdomains of vertebrate laminin A chains. The results indicate that laminin G subdomains should be considered individually, rather than merely as parts of a G-globule. A sequence of hydroxyamino acids contributes to a spacer between two of the subdomains. Stretches of hydroxyamino acids may be indicative of junctions between domains of extracellular Drosophila proteins.
authors.affiliation: Molecular Biology Institute, University of California, Los Angeles 90024-1570.
authors.forename: K
authors.initials: K
authors.lastname: Garrison
authors.forename: A J
authors.initials: AJ
authors.lastname: MacKrell
authors.forename: J H
authors.initials: JH
authors.lastname: Fessler
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002264:Carboxylic Acids / Q000737:chemistry; D004247:DNA; D004330:Drosophila / Q000235:genetics*; D019204:GTP-Binding Proteins / Q000378:metabolism; D006801:Humans; D007797:Laminin / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D012091:Repetitive Sequences, Nucleic Acid; D015183:Restriction Mapping; D016415:Sequence Alignment; D013045:Species Specificity
chemical_list: D002264:Carboxylic Acids; D007797:Laminin; D004247:DNA; D019204:GTP-Binding Proteins