ABCMdb

PMID: 9931011

Ramjeesingh M, Li C, Garami E, Huan LJ, Galley K, Wang Y, Bear CE
Walker mutations reveal loose relationship between catalytic and channel-gating activities of purified CFTR (cystic fibrosis transmembrane conductance regulator).
Biochemistry. 1999 Feb 2;38(5):1463-8., 1999-02-02 [PubMed]

Sentences

No. Mutations Sentence Comment

16 ABCC7 p.Gly551Asp Furthermore, we found that a disease-causing mutation in the "signature" motif of NBF1, namely, G551D, abrogated this activity (11). Login to comment 21 ABCC7 p.Lys1250Ala ABCC7 p.Lys1250Ala ABCC7 p.Lys464Ala While it was determined that the K464A mutation abrogated ATPase activity of the CFTR-NBF1 fusion protein (15), the effect of the K1250A mutation in the context of the CFTR-NBF2 fusion protein is not known. Login to comment 32 ABCC7 p.Lys1250Ala ABCC7 p.Lys464Ala A small cassette containing the specific mutation, i.e., a BspE1/SphI fragment for the K464A mutation or a Pm1I/Tth111I fragment for the K1250A mutation was subcloned into a new pBQ6.2 and then sequenced to confirm the introduction of the mutations. Login to comment 33 ABCC7 p.Lys1250Ala ABCC7 p.Lys464Ala Ultimately, K464A (as an XbaI/SphI fragment) or K1250A (as a Pm1I/Tth111I fragment) was subcloned into pBlueBac4 (Invitrogen, Carlsbad, CA) for baculovirus expression. Login to comment 123 ABCC7 p.Lys1250Ala ABCC7 p.Lys464Ala Disruption of the Chloride Channel ActiVity of the Intact Purified CFTR Protein by Mutation of the Walker A Lysine in either NBF1 or NBF2. We assessed the consequences of each of the Walker lysine mutations, K464A and K1250A, on the chloride channel activity of CFTR using two assays. Login to comment 166 ABCC7 p.Lys1250Ala The double mutant, CFTRK464A/K1250A, also exhibits negligible catalytic activity, comparable to that of CFTRK1250A (data not shown), supporting our suggestion that the two Walker sites are not symmetrical. Login to comment