title: Identification of a second poly(A) polymerase in Escherichia coli.
abstract: A second poly(A) polymerase (PAP II) has been identified in Escherichia coli using a strain carrying a deletion of pcnB (the structural gene for PAP I; Cao and Sarkar, 1992b) and pnp-7 (a null mutation in the structural gene for polynucleotide phosphorylase). While PAP I has a M(r) of 53,000, PAP II is a smaller protein with a native M(r)-35,000. PAP II differs from PAP I in preferring poly(A) over tRNA primers and being more thermolabile. The presence of multiple poly(A) polymerases in E. coli raises interesting questions regarding the role of polyadenylation in mRNA synthesis and decay.
authors.affiliation: Boston Biomedical Research Institute, MA 02114.
authors.forename: M P
authors.initials: MP
authors.lastname: Kalapos
authors.forename: G J
authors.initials: GJ
authors.lastname: Cao
authors.forename: S R
authors.initials: SR
authors.lastname: Kushner
authors.forename: N
authors.initials: N
authors.lastname: Sarkar
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins; D017353:Gene Deletion; D011061:Poly A / Q000032:analysis; D011062:Polynucleotide Adenylyltransferase / Q000302:isolation & purification* / Q000378:metabolism*; D011117:Polyribonucleotide Nucleotidyltransferase / Q000172:deficiency / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D012333:RNA, Messenger; D011061:Poly A; D011062:Polynucleotide Adenylyltransferase; C063643:pcnB protein, E coli; D011117:Polyribonucleotide Nucleotidyltransferase