A two-domain model for the R domain of the cystic fibrosis transmembrane conductance regulator based on sequence similarities.
CFTR belongs to a group of proteins sharing the structural motif of six transmembrane helices and a nucleotide binding domain. Unique to CFTR is the R domain, a charged cytoplasmic domain. Comparison of R domain sequences from ten species revealed that the N-terminal third is highly conserved, while the C-terminal two-thirds is poorly conserved. The R domain shows no strong sequence similarity to known proteins; however, 14 viral pol proteins show limited similarity to fragments of the R domain. Analysis revealed a relationship between the N- and C-terminal fragments of the R domain and two discontinuous fragments of the pol protein. These observations support a two-domain model for the R domain.
Dulhanty
A M
AM
Cystic Fibrosis Research Development Program, Hospital for Sick Children, Toronto, Ont., Canada.
Riordan
J R
JR
D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D015684:Gene Products, pol / Q000737:chemistry; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry*; D008969:Molecular Sequence Data; D010766:Phosphorylation; D017386:Sequence Homology, Amino Acid
C505032:CFTR protein, human; D015684:Gene Products, pol; D008565:Membrane Proteins; D019005:Cystic Fibrosis Transmembrane Conductance Regulator