Second-site suppressor mutations of inactivating substitutions at gly247 of the tetracycline efflux protein, Tet(B).
An Asp or Asn substitution for Gly247 in transmembrane helix 8 (TM-8) of Tet(B), the tetracycline efflux protein, eliminated tetracycline resistance. Second site suppressor mutations which partially restored resistance were located in TM-5, -8, -10, or -11 or in cytoplasmic loop 8-9 or loop 10-11. These results indicate physical proximity or functional relationships between TM-8 and these other regions of Tet(B).
Saraceni-Richards
C A
CA
The Center for Adaptation Genetics and Drug Resistance and the Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA.
Levy
S B
SB
D019943:Amino Acid Substitution; D001426:Bacterial Proteins / Q000235:genetics*; D005998:Glycine / Q000235:genetics; D009154:Mutation; D013489:Suppression, Genetic; D013753:Tetracycline Resistance / Q000235:genetics*
D001426:Bacterial Proteins; C086977:TETP protein, Clostridium perfringens; D005998:Glycine