PDBsum entry 2na0

Lyase activator

PDB id: 2na0

Contents

Protein chain

185 a.a.

PDB id:

2na0

Name:

Lyase activator

Title:

Nmr structure of guanylyl cyclase activator protein 1 (gcap1) mutant v77e in a ca2+-free/mg2+-bound activator state

Structure:

Guanylyl cyclase-activating protein 1. Chain: a. Synonym: gcap 1, guanylate cyclase activator 1a. Engineered: yes

Source:

Bos taurus. Bovine,cow,domestic cattle,domestic cow. Organism_taxid: 9913. Gene: guca1a, gcap1, guca1. Expressed in: escherichia coli. Expression_system_taxid: 562.

NMR struc:

15 models

Authors:

S.Lim,J.B.Ames

Key ref:

S.Lim et al. (2016). Structure of Guanylyl Cyclase Activator Protein 1 (GCAP1) Mutant V77E in a Ca2+-free/Mg2+-bound Activator State. J Biol Chem, 291, 4429-4441. PubMed id: 26703466 DOI: 10.1074/jbc.M115.696161

Date:

16-Dec-15 Release date: 30-Dec-15

Protein chain

P46065  (GUC1A_BOVIN) -  Guanylyl cyclase-activating protein 1 from Bos taurus

Seq: 205 a.a.

Struc: 185 a.a.*

* PDB and UniProt seqs differ at 2 residue positions (black crosses)

DOI no: 10.1074/jbc.M115.696161

J Biol Chem 291:4429-4441 (2016)

PubMed id: 26703466

Structure of Guanylyl Cyclase Activator Protein 1 (GCAP1) Mutant V77E in a Ca2+-free/Mg2+-bound Activator State.

S.Lim, I.V.Peshenko, E.V.Olshevskaya, A.M.Dizhoor, J.B.Ames.

ABSTRACT

GCAP1, a member of the neuronal calcium sensor subclass of the calmodulin superfamily, confers Ca(2+)-sensitive activation of retinal guanylyl cyclase 1 (RetGC1). We present NMR resonance assignments, residual dipolar coupling data, functional analysis, and a structural model of GCAP1 mutant (GCAP1(V77E)) in the Ca(2+)-free/Mg(2+)-bound state. NMR chemical shifts and residual dipolar coupling data reveal Ca(2+)-dependent differences for residues 170-174. An NMR-derived model of GCAP1(V77E) contains Mg(2+) bound at EF2 and looks similar to Ca(2+) saturated GCAP1 (root mean square deviations = 2.0 Å). Ca(2+)-dependent structural differences occur in the fourth EF-hand (EF4) and adjacent helical region (residues 164-174 called the Ca(2+) switch helix). Ca(2+)-induced shortening of the Ca(2+) switch helix changes solvent accessibility of Thr-171 and Leu-174 that affects the domain interface. Although the Ca(2+) switch helix is not part of the RetGC1 binding site, insertion of an extra Gly residue between Ser-173 and Leu-174 as well as deletion of Arg-172, Ser-173, or Leu-174 all caused a decrease in Ca(2+) binding affinity and abolished RetGC1 activation. We conclude that Ca(2+)-dependent conformational changes in the Ca(2+) switch helix are important for activating RetGC1 and provide further support for a Ca(2+)-myristoyl tug mechanism.