Sandbox 125: Difference between revisions
From Proteopedia
Jump to navigationJump to search
No edit summary |
No edit summary |
||
| Line 15: | Line 15: | ||
Kapβ2 is a superhelix comprised of 20 HEAT repeats (the name HEAT derives from Huntington, Elongation factor 3 A subunit of protein phosphatase 2A and Tor1 kinase), each of which consists of two anti-parallel helices. The electrostatic potential of the internal surface of Kapβ2 superhelix at the C-terminal arch is negative. HEAT repeats 9-13 and 14-18 form the binding site of Kapβ2 cargos while repeats 1-8 constitute the Ran GTPase binding site.3 Ran GTPase, a small 216-residue protein, is found more frequently in the nucleus and enables cargos to be released from Kapβ2. | Kapβ2 is a superhelix comprised of 20 HEAT repeats (the name HEAT derives from Huntington, Elongation factor 3 A subunit of protein phosphatase 2A and Tor1 kinase), each of which consists of two anti-parallel helices. The electrostatic potential of the internal surface of Kapβ2 superhelix at the C-terminal arch is negative. HEAT repeats 9-13 and 14-18 form the binding site of Kapβ2 cargos while repeats 1-8 constitute the Ran GTPase binding site.3 Ran GTPase, a small 216-residue protein, is found more frequently in the nucleus and enables cargos to be released from Kapβ2. | ||
<font size=3> '''Kapβ2 Binding and Conformational Change''' </font> | <font size=3> '''Kapβ2 Binding and Conformational Change''' </font> | ||
| Line 22: | Line 23: | ||
Recognition of the PY-NLS by Kapβ2 follows certain guidelines: | Recognition of the PY-NLS by Kapβ2 follows certain guidelines: | ||
(i) PY-NLS, when not bound to Kapβ2, lacks a secondary structure. | (i) PY-NLS, when not bound to Kapβ2, lacks a secondary structure. | ||
(ii) PY-NLS has an overall positive charge allowing for electrostatic compatibility with Kapβ2. | (ii) PY-NLS has an overall positive charge allowing for electrostatic compatibility with Kapβ2. | ||
(iii) General sequence for the PY-NLS is either a hydrophobic basic motif or a R-X2-5-P-Y motif at the C-terminus. | (iii) General sequence for the PY-NLS is either a hydrophobic basic motif or a R-X2-5-P-Y motif at the C-terminus. | ||
