1hfb: Difference between revisions
From Proteopedia
Jump to navigationJump to search
No edit summary |
No edit summary |
||
| Line 5: | Line 5: | ||
==Overview== | ==Overview== | ||
The betaalpha barrel is the common protein fold of numerous enzymes and, was proposed recently to be the result of gene duplication and fusion of, an ancient half-barrel. The initial enzyme of shikimate biosynthesis, possesses the additional feature of feedback regulation. The crystal, structure and kinetic studies on chimera and mutant proteins of yeast, 3-deoxy-d-arabino-heptulosonate-7-phosphate (DAHP) synthase from, Saccharomyces cerevisiae inhibited by phenylalanine (Aro3p) and DAHP, synthase S. cerevisiae inhibited by tyrosine (Aro4p) give insight into, important regions for regulation in the enzyme: The loop, which is, connecting the two half-barrels, and structural elements added to the, barrel are prerequisites for regulation and form a cavity on the, N-terminal side of the ... | The betaalpha barrel is the common protein fold of numerous enzymes and, was proposed recently to be the result of gene duplication and fusion of, an ancient half-barrel. The initial enzyme of shikimate biosynthesis, possesses the additional feature of feedback regulation. The crystal, structure and kinetic studies on chimera and mutant proteins of yeast, 3-deoxy-d-arabino-heptulosonate-7-phosphate (DAHP) synthase from, Saccharomyces cerevisiae inhibited by phenylalanine (Aro3p) and DAHP, synthase S. cerevisiae inhibited by tyrosine (Aro4p) give insight into, important regions for regulation in the enzyme: The loop, which is, connecting the two half-barrels, and structural elements added to the, barrel are prerequisites for regulation and form a cavity on the, N-terminal side of the betaalpha barrel. In the cavity of Aro4p at, position 226 is a glycine residue, which is highly conserved in all other, tyrosine-regulated DAHP synthases as well. Sequence alignments with, phenylalanine-regulated DAHP synthases including Aro3p show a highly, conserved serine residue at this position. An exchange of glycine to, serine and vice versa leads to a complete change in the regulation, pattern. Therefore the evolution of these differently feedback-inhibited, isoenzymes required gene duplication and a single mutation within the, internal extra element. Numerous additional amino acid substitutions, present in the contemporary isoenzymes are irrelevant for regulation and, occurred independently. | ||
==About this Structure== | ==About this Structure== | ||
1HFB is a | 1HFB is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Saccharomyces_cerevisiae Saccharomyces cerevisiae] with PEP as [http://en.wikipedia.org/wiki/ligand ligand]. Active as [http://en.wikipedia.org/wiki/Transferred_entry:_2.5.1.54 Transferred entry: 2.5.1.54], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=4.1.2.15 4.1.2.15] Structure known Active Site: AC1. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1HFB OCA]. | ||
==Reference== | ==Reference== | ||
| Line 22: | Line 22: | ||
[[Category: lyase]] | [[Category: lyase]] | ||
''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on | ''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Mon Nov 5 15:00:00 2007'' | ||
