Determining the basis of channel-tetramerization specificity by x-ray crystallography and a sequence-comparison algorithm: Family Values (FamVal).
We have developed a semiempirical algorithm called Family Values (FamVal), which identifies residues that encode functional specificity in a protein sequence. Given a multiple sequence alignment (MSA) grouped into functionally distinct subfamilies, FamVal calculates a specificity score for each subfamily at every amino acid position of an MSA. This algorithm was used to predict specificity-encoding positions within the tetramerization assembly (T1) domain of voltage-gated potassium (Kv) channel subfamilies Kv3 and Kv4. The importance of one such position (Arg to Ala at MSA position 93) was confirmed by in vitro pull-down assays. The structural basis of this assembly discrimination was elucidated by determining the crystal structure of the Kv4 T1 domain and comparing it to the Kv3 T1 domain.
Nanao
Max H
MH
Structural Biology Laboratory, The Salk Institute, La Jolla, CA 92037, USA.
Zhou
Wei
W
Pfaffinger
Paul J
PJ
Choe
Senyon
S
D000465:Algorithms; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D018360:Crystallography, X-Ray; D066298:In Vitro Techniques; D008958:Models, Molecular; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D015221:Potassium Channels / Q000737:chemistry / Q000235:genetics; D024642:Potassium Channels, Voltage-Gated / Q000737:chemistry* / Q000235:genetics*; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry* / Q000235:genetics*; D051381:Rats; D016415:Sequence Alignment / Q000706:statistics & numerical data*; D051672:Shal Potassium Channels; D051670:Shaw Potassium Channels
D015221:Potassium Channels; D024642:Potassium Channels, Voltage-Gated; D011506:Proteins; D051672:Shal Potassium Channels; D051670:Shaw Potassium Channels