User:Andrea Foote/Sandbox 1: Difference between revisions

No edit summary
No edit summary
Line 8: Line 8:
Purα functions as a dimer composed of two intramolecular domains and one intermolecular domain. The Purα monomer contains three semi-conserved repeated amino acid sequences, named in order from N->C: PUR repeats I, II, and III. These repeats fold to form two domains: <scene name='78/786627/5fgp_intro/8'>PUR repeats I and II</scene> associating to form the I-II domain or “intramolecular domain”, while <scene name='78/786627/5fgo_repeatiii/2'>PUR repeat III</scene> facilitates dimerization through association with a repeat III from a second Purα monomer or repeat III of Purβ. Each PUR repeat is connected by flexible linker regions. Each PUR repeat contains a beta-sheet composed of four beta-strands, followed by a single alpha-helix. While Purα is not yet officially classified by SCOP or CATH, its structure is that of an α+β protein.
Purα functions as a dimer composed of two intramolecular domains and one intermolecular domain. The Purα monomer contains three semi-conserved repeated amino acid sequences, named in order from N->C: PUR repeats I, II, and III. These repeats fold to form two domains: <scene name='78/786627/5fgp_intro/8'>PUR repeats I and II</scene> associating to form the I-II domain or “intramolecular domain”, while <scene name='78/786627/5fgo_repeatiii/2'>PUR repeat III</scene> facilitates dimerization through association with a repeat III from a second Purα monomer or repeat III of Purβ. Each PUR repeat is connected by flexible linker regions. Each PUR repeat contains a beta-sheet composed of four beta-strands, followed by a single alpha-helix. While Purα is not yet officially classified by SCOP or CATH, its structure is that of an α+β protein.


[[Image:180503 PurA Why2 comparison.jpg|thumb|right|300px| PUR domains are structurally similar to the fold in Whirly proteins. Left: PUR repeat I-II (5fgp), right: WHY2 (3n1k).]]
[[Image:180503 PurA Why2 comparison.jpg|thumb|right|300px| PUR domains are structurally similar to the fold in Whirly proteins. Left: PUR repeat I-II ([[5fgp]]), right: WHY2 ([[3n1k]]).]]
The domains of Purα have been described as "Whirly-like" folds because of their structural similarity to the DNA-binding Whirly class of proteins found in plants.<ref>PMID:19846792</ref> Whirlys are also ssDNA binding proteins, however unlike Purα they are not sequence-specific.
The domains of Purα have been described as "Whirly-like" folds because of their structural similarity to the DNA-binding Whirly class of proteins found in plants.<ref>PMID:19846792</ref> Whirlys are also ssDNA binding proteins, however unlike Purα they are not sequence-specific.