SASDAQ4: 6:3 complex of GAD:CaM (Calmodulin + Glutamate decarboxylase, GAD)

Basic information

• Entry: Database: SASBDB / ID: SASDAQ4

Sample

6:3 complex of GAD:CaM

• Calmodulin (protein), Homo sapiens
• Glutamate decarboxylase (protein), GAD, Petunia x hybrida

Function / homology

Function:

glutamate decarboxylase / glutamate decarboxylase activity / : / : / positive regulation of cyclic-nucleotide phosphodiesterase activity / : / L-glutamate catabolic process / establishment of protein localization to mitochondrial membrane / negative regulation of peptidyl-threonine phosphorylation / type 3 metabotropic glutamate receptor binding / positive regulation of DNA binding / negative regulation of high voltage-gated calcium channel activity / response to corticosterone / positive regulation of peptidyl-threonine phosphorylation / nitric-oxide synthase binding / negative regulation of calcium ion export across plasma membrane / regulation of synaptic vesicle exocytosis / regulation of cardiac muscle cell action potential / positive regulation of ryanodine-sensitive calcium-release channel activity / regulation of cell communication by electrical coupling involved in cardiac conduction / negative regulation of ryanodine-sensitive calcium-release channel activity / regulation of synaptic vesicle endocytosis / positive regulation of protein autophosphorylation / protein phosphatase activator activity / adenylate cyclase binding / catalytic complex / detection of calcium ion / regulation of cardiac muscle contraction / positive regulation of protein serine/threonine kinase activity / phosphatidylinositol 3-kinase binding / regulation of cardiac muscle contraction by regulation of the release of sequestered calcium ion / activation of adenylate cyclase activity / regulation of release of sequestered calcium ion into cytosol by sarcoplasmic reticulum / enzyme regulator activity / regulation of calcium-mediated signaling / titin binding / voltage-gated potassium channel complex / substantia nigra development / calcium channel complex / nitric-oxide synthase regulator activity / response to amphetamine / positive regulation of nitric-oxide synthase activity / adenylate cyclase activator activity / regulation of heart rate / protein serine/threonine kinase activator activity / sarcomere / regulation of cytokinesis / spindle microtubule / mitochondrial membrane / synaptic vesicle membrane / response to calcium ion / spindle pole / calcium-dependent protein binding / G2/M transition of mitotic cell cycle / disordered domain specific binding / pyridoxal phosphate binding / myelin sheath / growth cone / vesicle / transmembrane transporter binding / calmodulin binding / G protein-coupled receptor signaling pathway / protein domain specific binding / centrosome / calcium ion binding / protein kinase binding / protein-containing complex / nucleus / plasma membrane / cytosol / cytoplasm

Domain/homology:

Glutamate decarboxylase / Pyridoxal phosphate-dependent decarboxylase / Pyridoxal-dependent decarboxylase conserved domain / EF-hand domain pair / Pyridoxal phosphate-dependent transferase, major domain / Pyridoxal phosphate-dependent transferase / EF-hand, calcium binding motif / EF-Hand 1, calcium-binding site / EF-hand calcium-binding domain. / EF-hand calcium-binding domain profile. / EF-hand domain / EF-hand domain pair

Component:

Calmodulin-3 / Glutamate decarboxylase

• Biological species: Homo sapiens (human); Petunia x hybrida (garden petunia)
• Citation: Journal: J Mol Biol / Year: 2009; Title: A common structural basis for pH- and calmodulin-mediated regulation in plant glutamate decarboxylase.; Authors: Heinz Gut / Paola Dominici / Stefania Pilati / Alessandra Astegno / Maxim V Petoukhov / Dmitri I Svergun / Markus G Grütter / Guido Capitani / ; Abstract: Glutamate decarboxylase (Gad) catalyzes glutamate to gamma-aminobutyrate conversion. Plant Gad is a approximately 340 kDa hexamer, involved in development and stress response, and regulated by pH and binding of Ca(2+)/calmodulin (CaM) to the C-terminal domain. We determined the crystal structure of Arabidopsis thaliana Gad1 in its CaM-free state, obtained a low-resolution structure of the calmodulin-activated Gad complex by small-angle X-ray scattering and identified the crucial residues, in the C-terminal domain, for regulation by pH and CaM binding. CaM activates Gad1 in a unique way by relieving two C-terminal autoinhibition domains of adjacent active sites, forming a 393 kDa Gad1-CaM complex with an unusual 1:3 stoichiometry. The complex is loosely packed: thanks to the flexible linkers connecting the enzyme core with the six C-terminal regulatory domains, the CaM molecules retain considerable positional and orientational freedom with respect to Gad1. The complex thus represents a prototype for a novel CaM-target interaction mode. Thanks to its two levels of regulation, both targeting the C-terminal domain, Gad can respond flexibly to different kinds of cellular stress occurring at different pH values.

Contact author

• Maxim Petoukhov (EMBL-Hamburg, European Molecular Biology Laboratory (EMBL) - Hamburg outstation, Notkestraße 85, Geb. 25A, 22607 Hamburg, Deutschland, Germany)

Models

• Model #67: ; Type: mix / Software: Bunch / Radius of dummy atoms: 1.90 A / Symmetry: P6/P1; Search similar-shape structures of this assembly by Omokage search (details)

Sample

• Sample: Name: 6:3 complex of GAD:CaM / Sample MW: 357.22 kDa / Entity id: 58 / 61
• Buffer: Name: HEPES / Concentration: 50.00 mM / PK: 7 / pH: 7.5 / Comment: 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid / Composition: KCl 50.000 mM

Entity #58

Type: protein / Description: Calmodulin / Formula weight: 16.84 / Num. of mol.: 1 / Source: Homo sapiens / References: UniProt: P62158
Sequence:

MADQLTEEQI AEFKEAFSLF DKDGDGTITT KELGTVMRSL GQNPTEAELQ DMINEVDADG NGTIDFPEFL TMMARKMKDT DSEEEIREAF RVFDKDGNGY ISAAELRHVM TNLGEKLTDE EVDEMIREAD IDGDGQVNYE EFVQMMTAK

Entity #61

Name: GAD / Type: protein / Description: Glutamate decarboxylase / Formula weight: 56.73 / Num. of mol.: 6 / Source: Petunia x hybrida / References: UniProt: Q07346
Sequence:

MVLSKTVSQS DVSIHSTFAS RYVRTSLPRF KMPDNSIPKE AAYQIINDEL MLDGNPRLNL ASFVTTWMEP ECDKLMMDSI NKNYVDMDEY PVTTELQNRC VNMIAHLFNA PLEDGETAVG VGTVGSSEAI MLAGLAFKRK WQNKMKAQGK PCDKPNIVTG ANVQVCWEKF ARYFEVELKE VKLSEGYYVM DPEKAVEMVD ENTICVAAIL GSTLNGEFED VKRLNDLLVE KNKETGWDTP IHVDAASGGF IAPFIYPELE WDFRLPLVKS INVSGHKYGL VYAGIGWVVW RNKDDLPDEL IFHINYLGAD QPTFTLNFSK GSSQVIAQYY QLIRLGYEGY KNVMENCQEN ASVLREGLEK TGRFNIISKE IGVPLVAFSL KDNRQHNEFE ISETLRRFGW IVPAYTMPPN AQHITVLRVV IREDFSRTLA ERLVRDIEKV LHELDTLPAR VNAKLAVAEE QAAANGSEVH KKTDSEVQLE MITAWKKFVE EKKKKTNRVC

Experimental information

• Beam: Instrument name: DORIS III X33 / City: Hamburg / 国: Germany / Type of source: X-ray synchrotron
• Detector: Name: MAR 345 Image Plate

Scan

Title: GAD:CaM complex / Measurement date: Nov 9, 2004 / Unit: 1/nm /

	Min	Max
Q	0.1557	4.483

Distance distribution function P(R)

Sofotware P(R): GNOM 4.6 / Number of points: 285 /

	Min	Max
Q	0.1568	1.396
P(R) point	1	285
R	0	23.17

Result

I0 from Guinier: 87600 / Rg from Guinier: 5.85 nm / Type of curve: single_conc /

	Experimental	Porod
MW	400 kDa	-
Volume	-	630 nm3

/

	Min	Max
D	-	23
Guinier point	1	29