Sandbox Reserved 349: Difference between revisions
From Proteopedia
Jump to navigationJump to search
Jon Waller (talk | contribs) No edit summary |
Jon Waller (talk | contribs) No edit summary |
||
| Line 3: | Line 3: | ||
=Porphobilinogen deaminase= | =Porphobilinogen deaminase= | ||
==Structure== | ==Structure== | ||
PBGD is a three-domain polypeptide with each domain consisting of approximately 110 amino acids; the human variant has an additional 29 residue loop in domain three that extends hydrogen bonding across domain three while ''E.coli'' PBGD is lacking this extended loop <ref name="Raj">PMID: 19207107</ref>. In the active site, a unique molecule known as <scene name='Template:Sandbox_Reserved_349/Dpm_site/2'>Dipyrromethane</scene> interacts with porphobilinogen and anchors it in place<ref name="Raj">PMID: 19207107</ref>. Ordered <scene name='Sandbox_Reserved_349/Sulfate_and_serarg/1'>Sulfate ions</scene> are also hydrogen bonded with Arg26 and Ser28 residues near the active site that are highly conserved amongst human and ''E.coli'' variants of PBGD<ref name="Raj">PMID: 19207107</ref>. | |||
Although PBGD appears to have hydrogen bonding capabilities between two identical PBGD units, at physiological pH, these interactions account for a dimer interface of approximately 5% while average dimer interface between subunits is 16%<ref name="Raj">PMID: 19207107</ref>. Therefore, it is generally assumed that this protein is active naturally as a monomeric enzyme<ref name="Raj">PMID: 19207107</ref>. | Although PBGD appears to have hydrogen bonding capabilities between two identical PBGD units, at physiological pH, these interactions account for a dimer interface of approximately 5% while average dimer interface between subunits is 16%<ref name="Raj">PMID: 19207107</ref>. Therefore, it is generally assumed that this protein is active naturally as a monomeric enzyme<ref name="Raj">PMID: 19207107</ref>. | ||
==Function== | ==Function== | ||
