Regulation of transporters associated with antigen processing (TAPs) by nucleotide binding to, and hydrolysis by, Walker consensus sequences
The TAP transporters (TAPI/TAP2) belong to the large family of ATPbinding-cassette (ABC) transporters which translocate a variety of solutes across cellular membranes in an ATP-dependent fashion. ABC transporters are regulated by nucleotide triphosphate binding to, and hydrolysis by, several conserved sequence elements termed Walker A and B motifs which are located in the two hydrophilic ABC domains found in all members of the family. Nucleotide binding and hydrolysis are thought to be associated with sequential conformational changes that together constitute a transport cycle which starts with a high affinity substrate binding site on one side of the membrane and ends with a low affinity site on the other side (1).
KeywordsPeptide Binding Nucleotide Binding Transport Cycle Nucleotide Hydrolysis Equivalent Mutation
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