Molecular Playground/DnaK: Difference between revisions
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Molecular Playground banner: DnaK, a central hub in maintaining proteostasis in E. coli | Molecular Playground banner: DnaK, a central hub in maintaining proteostasis in E. coli | ||
<scene name='60/609794/Adp-dnak_1/ | <scene name='60/609794/Adp-dnak_1/4'>DnaK in the extended conformation</scene> | ||
The E. coli Hsp70, DnaK, is a crucial protein chaperone whose function is to reduce bind exposed hydrohpobic residues of unfolded proteins, which prevents aggregation and rescues the nascent chain from kinetic traps along the folding pathway. Hsp70 protein chaperones switch between an <scene name='60/609794/Atp-dnak/1'>ATP-bound</scene>, low-substrate affinity form and an <scene name='60/609794/Adp-dnak_1/ | The E. coli Hsp70, DnaK, is a crucial protein chaperone whose function is to reduce bind exposed hydrohpobic residues of unfolded proteins, which prevents aggregation and rescues the nascent chain from kinetic traps along the folding pathway. Hsp70 protein chaperones switch between an <scene name='60/609794/Atp-dnak/1'>ATP-bound</scene>, low-substrate affinity form and an <scene name='60/609794/Adp-dnak_1/4'>ADP-bound</scene>, high substrate affinity form during their allosteric cycle.[http://www.ncbi.nlm.nih.gov/pubmed/23123194?dopt=Abstract] [http://www.ncbi.nlm.nih.gov/pubmed/19439666?dopt=Abstract] Hsp70 protein chaperones are ubiquitously found in almost all known organisms and cell types and represent a potential target for anti-cancer and neurodegenerative therapies.[http://www.ncbi.nlm.nih.gov/pubmed/21403392] | ||
===Structure=== | ===Structure=== | ||
DnaK is a 638 residue protein of approximately 70 kDa. The protein can be thought to be made up of two domains, the N-terminal nucleotide-binding domain (<scene name='60/609794/Nbd/4'>NBD</scene>) (residues 1-388), the C-terminal substrate-binding domain (<scene name='60/609794/Sbd/ | DnaK is a 638 residue protein of approximately 70 kDa. The protein can be thought to be made up of two domains, the N-terminal nucleotide-binding domain (<scene name='60/609794/Nbd/4'>NBD</scene>) (residues 1-388), the C-terminal substrate-binding domain (<scene name='60/609794/Sbd/2'>SBD</scene>) (residues 393-638), which are divided by the <scene name='60/609794/Linker/1'>interdomain linker</scene> (residues 389-392, shown in purple). The NBD is further divided into four subdomains: <scene name='60/609794/Subdomain_ia/2'>IA</scene> (residues 1-37, 112-184, 363-383, shown in red), <scene name='60/609794/Subdomain_ib/2'>IB</scene> (residues 38-111, shown in green), <scene name='60/609794/Subdomain_iia/2'>IIA</scene> (residues 185-227, 310-362, shown in gold), and <scene name='60/609794/Subdomain_iib/2'>IIB</scene> (residues 228-309, shown in purple). The SBD of DnaK consists of a <scene name='60/609794/Beta_basket/1'>beta-basket</scene> (residues 393-507), an <scene name='60/609794/Helical_lid/1'>alpha-helical lid</scene> (residues 508-605), and a disordered C-terminal tail (not shown due to lack of available crystal structure).[http://www.ncbi.nlm.nih.gov/pubmed/22576356] | ||
===Function=== | ===Function=== | ||