Sandbox Reserved 773: Difference between revisions

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== Sequence and Structure ==

Histidine Decarboxylase is considered to be a homo-dimer when one observe its [[biological assembly]] <ref name=mast/>. A homodimer is a [[quaternary structure]] formed by two identical monomers or protein chains.

Histidine Decarboxylase is considered to be a homo-dimer when one observe its [[biological assembly]] <ref name=mast/>. A homodimer is a [[quaternary structure]] formed by two identical monomers or protein chains. In human, three human HDC (hHDC) homodimers can be joined together to form a trimer [[asymmetric unit]] <ref name=jbc/> <ref name=xray>PMID: 22684068</ref>. Thus, one can use the nomenclature “trimer of dimer” to suggest the complex might dissociate into smaller subunits before dissociating into monomers. The asymmetrical unit can be seen in Figure 1. Specifically, Cys-180 and Cys-418 are primary responsible for the oligomerization process of HDC <ref name=xray/>.

Each monomer is divided into 3 structural <scene name='56/564049/3domain/1'>domains</scene>: <scene name='56/564049/Nterm/1'>N-terminal</scene> (~2-71), large domain (71-371), and small domain (372-477) (green link/figure 5) <ref name=jbc/>. A monomer is also composed of 49% helical structure and 13% beta sheet <ref name=4e10/>. One distinctively long α-helix which span from Val-359 to Arg-393 connects the large and small domains together (Figure 2). Through hydrophobic effect, the N-terminal regions of the two monomers interact with each other extensively. At the same time, the large domains interact extensively due to electrostatic interactions. Thus, the N-terminal regions and large domains form the dimer interfaces of HDC <ref name=jbc/>.

In human, three human HDC (hHDC) homodimers can be joined together to form a trimer [[asymmetric unit]] <ref name=jbc/> <ref name=xray>PMID: 22684068</ref>. Thus, one can use the nomenclature “trimer of dimer” to suggest the complex might dissociate into smaller subunits before dissociating into monomers. The asymmetrical unit can be seen in Figure 1. Specifically, Cys-180 and Cys-418 are primary responsible for the oligomerization process of HDC <ref name=xray/>.

Sandbox Reserved 773: Difference between revisions

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 == Sequence and Structure ==
-Histidine Decarboxylase is considered to be a homo-dimer when one observe its [[biological assembly]] <ref name=mast/>. A homodimer is a [[quaternary structure]] formed by two identical monomers or protein chains.
+Histidine Decarboxylase is considered to be a homo-dimer when one observe its [[biological assembly]] <ref name=mast/>. A homodimer is a [[quaternary structure]] formed by two identical monomers or protein chains. In human, three human HDC (hHDC) homodimers can be joined together to form a trimer [[asymmetric unit]] <ref name=jbc/> <ref name=xray>PMID: 22684068</ref>. Thus, one can use the nomenclature “trimer of dimer” to suggest the complex might dissociate into smaller subunits before dissociating into monomers. The asymmetrical unit can be seen in Figure 1. Specifically, Cys-180 and Cys-418 are primary responsible for the oligomerization process of HDC <ref name=xray/>.
 Each monomer is divided into 3 structural <scene name='56/564049/3domain/1'>domains</scene>: <scene name='56/564049/Nterm/1'>N-terminal</scene> (~2-71), large domain (71-371), and small domain (372-477) (green link/figure 5) <ref name=jbc/>. A monomer is also composed of 49% helical structure and 13% beta sheet <ref name=4e10/>. One distinctively long α-helix which span from Val-359 to Arg-393 connects the large and small domains together (Figure 2). Through hydrophobic effect, the N-terminal regions of the two monomers interact with each other extensively. At the same time, the large domains interact extensively due to electrostatic interactions. Thus, the N-terminal regions and large domains form the dimer interfaces of HDC <ref name=jbc/>.
-In human, three human HDC (hHDC) homodimers can be joined together to form a trimer [[asymmetric unit]] <ref name=jbc/> <ref name=xray>PMID: 22684068</ref>. Thus, one can use the nomenclature “trimer of dimer” to suggest the complex might dissociate into smaller subunits before dissociating into monomers. The asymmetrical unit can be seen in Figure 1. Specifically, Cys-180 and Cys-418 are primary responsible for the oligomerization process of HDC <ref name=xray/>.
 <Structure load='4e1o' size='500' frame='true' align='right' caption='Asymmetric unit of Histidine Decarboxylase complex with 6 PLP-HME substrate-analogs (atoms shown in orange, grey, and blue) bound to each of the active sites.' scene='Insert optional scene name here' />