The antirepressor of phage P1 Isolation and interaction with the C1 repressor of P1 and P7

FEBS Letters

Heinrich, Jochen¹  Choli, Theodora¹  Heisig, Anke¹  Schuster, Heinz¹  Riedel, Hans-Dieter¹ 

[1] Max-Planck-Institut für Molekulare Genetik, Ihnestrasse 73, D-14195 Berlin, Germany

关键词: Regulatory protein;    Translational coupling;    In-frame start codon;    T7 RNA polymerase transcription/translation system;    kb;    kilobase;    bp;    base pairs;    kDa;    kilodalton;    IPTG;    isopropyl-β-D-thiogalactopyranoside;    SDS-PAGE;    sodium dodecyl sulfate-polyacrylamide gel electrophoresis;   

DOI  :  10.1016/0014-5793(93)81705-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Two antirepressor proteins, Ant1 and Ant2, of molecular weight 42 and 32 kDa, respectively, are encoded by P1 as a single open reading frame, with the smaller protein initiating at an in-frame start codon. Another open reading frame, icd, 5′ upstream of and overlapping ant1 is required for ant1 expression. Using appropriate ant gene-carrying plasmids we have overproduced and purified Ant½ in the form of a protein complex and Ant2 as a single protein. Sequence analysis confirmed the N-terminal amino acids predicted from the DNA sequence of ant1/ant2, except that the N-terminal methionine is missing in the Ant2 protein. Under appropriate conditions the C1 repressors of phages P1 and P7 specifically co-precipitate with the Ant½ complex but not with Ant2 protein alone. The results suggest that the antirepressor may exert its C1-inactivating function by a direct protein—protein interaction.

【 授权许可】

Unknown