1PX2

Crystal Structure of Rat Synapsin I C Domain Complexed to Ca.ATP (Form 1)

Summary for 1PX2

• Entry DOI: 10.2210/pdb1px2/pdb
• Related: 1AUX 1PK8
• Descriptor: Synapsin I, CALCIUM ION, ADENOSINE-5'-TRIPHOSPHATE, ... (4 entities in total)
• Functional Keywords: atp binding, atp grasp, calcium (ii) ion, membrane protein
• Biological source: Rattus norvegicus (Norway rat)
• Cellular location: Cell junction, synapse: P09951
• Total number of polymer chains: 2
• Total formula weight: 92173.31

Authors

Brautigam, C.A.,Chelliah, Y.,Deisenhofer, J. (deposition date: 2003-07-02, release date: 2004-03-23, Last modification date: 2024-03-13)

Primary citation

Brautigam, C.A.,Chelliah, Y.,Deisenhofer, J.
Tetramerization and ATP binding by a protein comprising the A, B, and C domains of rat synapsin I.
J.Biol.Chem., 279:11948-11956, 2004

PubMed Abstract: Synapsins are multidomain proteins that are critical for regulating neurotransmitter release in vertebrates. In the present study, two crystal structures of the C domain of rat synapsin I (rSynI-C) in complex with Ca(2+) and ATP reveal that this protein can form a tetramer and that a flexible loop (the "multifunctional loop") contacts bound ATP. Further experiments were carried out on a protein comprising the A, B, and C domains of rat synapsin I (rSynI-ABC). An ATP-stabilized tetramer of rSynI-ABC is observed during velocity sedimentation and size-exclusion chromatographic experiments. These hydrodynamic results also indicate that the A and B domains exist in an extended conformation. Calorimetric measurements of ATP binding to wild-type and mutant rSynI-ABC demonstrate that the multifunctional loop and a cross-tetramer contact are important for ATP binding. The evidence supports a view of synapsin I as an ATP-utilizing, tetrameric protein made up of monomers that have a flexible, extended N terminus.

PubMed: 14688264
DOI: 10.1074/jbc.M312015200

Experimental method

X-RAY DIFFRACTION (2.23 Å)