Transformation of a fragment of beta-structural bacteriophage T4 adhesin to stable alpha-helical trimer.
Gene product 12 of bacteriophage T4, adhesin, serves to adhere the virus to host cells. Adhesin is a fibrous homotrimer, and a novel tertiary structure element, a beta-helix, is supposed to be a major structural feature of this protein. We have constructed two truncated gp12 mutants, 12N1 and 12N2, containing 221 and 135 N-terminal residues, respectively. When expressed in E. coli cells, these gp12 fragments formed labile beta-structural trimers. Another hybrid protein, 12FN, containing 179 N-terminal amino acid residues of gp12 fused to the C-terminal domain (31 amino acids) of T4 fibritin, was shown to have a trimeric proteolytically resistant alpha-helical structure. This structure is probably similar to that of fibritin, which has a triple alpha-helical coiled-coil structure. Hence, we have demonstrated the possibility of global transformation of fibrous protein structure using fusion with a C-terminal domain that initiates trimerization.
Miroshnikov
K A
KA
Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, 117071 Russia.
Sernova
N V
NV
Shneider
M M
MM
Mesyanzhinov
V V
VV
D018829:Adhesins, Bacterial / Q000737:chemistry* / Q000302:isolation & purification; D000595:Amino Acid Sequence; D017122:Bacteriophage T4 / Q000737:chemistry*; D002942:Circular Dichroism; D004247:DNA / Q000378:metabolism; D019281:Dimerization; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000378:metabolism; D008969:Molecular Sequence Data; D016296:Mutagenesis; D016133:Polymerase Chain Reaction; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D014357:Trypsin / Q000378:metabolism
D018829:Adhesins, Bacterial; D004247:DNA; D014357:Trypsin