3EF1: The Structure Of Fcp1, An Essential Rna Polymerase Ii Ctd Phosphatase

Kinases and phosphatases regulate mRNA synthesis and processing by phosphorylating and dephosphorylating the C-terminal domain (CTD) of the largest subunit of RNA polymerase II. Fcp1 is an essential CTD phosphatase that preferentially hydrolyzes Ser2-PO(4) of the tandem YSPTSPS CTD heptad array. Fcp1 crystal structures were captured at two stages of the reaction pathway: a Mg-BeF(3) complex that mimics the aspartylphosphate intermediate and a Mg-AlF(4)(-) complex that mimics the transition state of the hydrolysis step. Fcp1 is a Y-shaped protein composed of an acylphosphatase domain located at the base of a deep canyon formed by flanking modules that are missing from the small CTD phosphatase (SCP) clade: an Fcp1-specific helical domain and a C-terminal BRCA1 C-terminal (BRCT) domain. The structure and mutational analysis reveals that Fcp1 and Scp1 (a Ser5-selective phosphatase) adopt different CTD-binding modes; we surmise the CTD threads through the Fcp1 canyon to access the active site.
PDB ID: 3EF1Download
MMDB ID: 68288
PDB Deposition Date: 2008/9/7
Updated in MMDB: 2008/12
Experimental Method:
x-ray diffraction
Resolution: 2.15  Å
Source Organism:
Similar Structures:
Biological Unit for 3EF1: monomeric; determined by author and by software (PISA)
Molecular Components in 3EF1
Label Count Molecule
Protein (1 molecule)
RNA Polymerase II Subunit a C-terminal Domain Phosphatase(Gene symbol: fcp1)
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB