Putative Interhelical Interactions within the PheP Protein Revealed by Second-Site Suppressor Analysis

AUTOR(ES)

Dogovski, C.

FONTE

American Society for Microbiology

RESUMO

Highly conserved glycine residues within span I and span II of the phenylalanine and tyrosine transporter PheP were shown to be important for the function of the wild-type protein. Replacement by amino acids with increasing side chain volume led to progressive loss of transport activity. Second-site suppression studies performed with a number of the primary mutants revealed a tight packing arrangement between spans I and II that is important for function and an additional interaction between spans I and III. We also postulate that a third motif, GXXIG, present in span I and highly conserved within different members of the amino acid-polyamine-organocation family, may function as a dimerization motif. Surprisingly, other highly conserved residues, such as Y60 and L41, could be replaced by various residues with no apparent loss of activity.

Documentos Relacionados

• Study of Second-Site Suppression in the pheP Gene for the Phenylalanine Transporter of Escherichia coli
• Mechanism of rescue of common p53 cancer mutations by second-site suppressor mutations
• Second-Site Suppressor Mutations of Inactivating Substitutions at Gly247 of the Tetracycline Efflux Protein, Tet(B)
• Second-site revertants of the P1 copN22 copy mutant.
• Use of second-site suppressor mutations in Drosophila to identify components of the transcriptional machinery.