title: Cloning and characterization of human liver cDNA encoding a protein S precursor.
abstract: Human liver cDNA encoding a protein S precursor was isolated from two cDNA libraries by two different techniques. Based upon the frequency of positive clones, the abundance of mRNA for protein S is approximately 0.01%. Blot hybridization of electrophoretically fractionated poly(A)+ RNA revealed a major mRNA approximately 4 kilobases long and two minor forms of approximately 3.1 and approximately equal to 2.6 kilobases. One of the cDNA clones contains a segment encoding a 676 amino acid protein S precursor, as well as 108 and 1132 nucleotides of 5' and 3' noncoding sequence, respectively, plus a poly(A) region at the 3' end. The cDNAs are adenosine plus thymidine-rich (60%) except for the 5' noncoding region, where 78% of the nucleotides are guanosine or cytosine. The protein precursor consists of a 41 amino acid "leader" peptide followed by 635 amino acids corresponding to mature protein S. Comparison of the mature protein region with homologous vitamin K-dependent plasma proteins shows that it is composed of the following domains: an amino-terminal gamma-carboxyglutamic acid-rich region of 37 amino acids; a 36 amino acid linker region rich in hydroxy amino acids; four epidermal growth factor-like segments, each approximately 45 amino acids long; and a 387 amino acid carboxyl-terminal domain of unrecognized structure and unknown function.
authors.forename: J
authors.initials: J
authors.lastname: Hoskins
authors.forename: D K
authors.initials: DK
authors.lastname: Norman
authors.forename: R J
authors.initials: RJ
authors.lastname: Beckmann
authors.forename: G L
authors.initials: GL
authors.lastname: Long
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D001798:Blood Proteins / Q000235:genetics; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism*; D005796:Genes; D006023:Glycoproteins / Q000235:genetics*; D006801:Humans; D008099:Liver / Q000378:metabolism*; D009693:Nucleic Acid Hybridization; D010957:Plasmids; D011498:Protein Precursors / Q000235:genetics*; D017293:Protein S; D012689:Sequence Homology, Nucleic Acid
chemical_list: D001798:Blood Proteins; D006023:Glycoproteins; D011498:Protein Precursors; D017293:Protein S; C050930:protein S precursor; D004247:DNA