TY - JOUR
T1 - Dissecting cAMP binding domain A in the R1α subunit of cAMP-dependent protein kinase
T2 - Distinct subsites for recognition of cAMP and the catalytic subunit
AU - Huang, Lily Jun Shen
AU - Taylor, Susan S.
N1 - Copyright:
Copyright 2007 Elsevier B.V., All rights reserved.
PY - 1998/10/9
Y1 - 1998/10/9
N2 - The two gene-duplicated cAMP binding domains in the regulatory subunits of cAMP dependent protein kinase are each comprised of an A helix, an eight- stranded β-barrel, and a B and C helix (1). The A domain is required for high affinity binding to C, while the B domain regulates access to the A domain. Using a combination of a yeast two-hybrid screen coupled with deletion analysis, cAMP binding domain A of R(I) was dissected into two structurally and functionally distinct subsites, one that binds cAMP and another that binds the C subunit. The minimum stable subdomain required for binding to C in the 1-3 micromolar range is composed of residues 94-169, while residues 236-244, mapped to the C helix of cAMP binding domain A, were defined as a second surface necessary for high affinity (5-10 nanomolar) binding to C. This portion of the C helix, due to its position directly between the two subsites, serves as a molecular switch for either a cAMP- bound conformation or a C-bound conformation and can thus modulate interactions of cAMP binding domain A with cAMP, with C, and with cAMP binding domain B.
AB - The two gene-duplicated cAMP binding domains in the regulatory subunits of cAMP dependent protein kinase are each comprised of an A helix, an eight- stranded β-barrel, and a B and C helix (1). The A domain is required for high affinity binding to C, while the B domain regulates access to the A domain. Using a combination of a yeast two-hybrid screen coupled with deletion analysis, cAMP binding domain A of R(I) was dissected into two structurally and functionally distinct subsites, one that binds cAMP and another that binds the C subunit. The minimum stable subdomain required for binding to C in the 1-3 micromolar range is composed of residues 94-169, while residues 236-244, mapped to the C helix of cAMP binding domain A, were defined as a second surface necessary for high affinity (5-10 nanomolar) binding to C. This portion of the C helix, due to its position directly between the two subsites, serves as a molecular switch for either a cAMP- bound conformation or a C-bound conformation and can thus modulate interactions of cAMP binding domain A with cAMP, with C, and with cAMP binding domain B.
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U2 - 10.1074/jbc.273.41.26739
DO - 10.1074/jbc.273.41.26739
M3 - Article
C2 - 9756917
AN - SCOPUS:0032500591
SN - 0021-9258
VL - 273
SP - 26739
EP - 26746
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 41
ER -