Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Monomer - A1 

Biological assembly 1 generated by PISA (software)

Macromolecule Content

• Total Structure Weight: 13.07 kDa 
• Atom Count: 911 
• Modelled Residue Count: 108 
• Deposited Residue Count: 108 
• Unique protein chains: 1
• Unique nucleic acid chains: 1

 2XC7

Solution Structure of PHAX-RBD in complex with ssRNA

• PDB DOI:  https://doi.org/10.2210/pdb2XC7/pdb
• NDB: 2XC7

• Classification: RNA BINDING PROTEIN
• Organism(s): Homo sapiens
• Expression System: Escherichia coli BL21
• Mutation(s): No 


• Deposited: 2010-04-18 Released: 2010-04-28 
• Deposition Author(s): Mourao, A., Mackereth, C.D., Varrot, A., Cusack, S., Sattler, M.

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Experimental Data Snapshot

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 10 
• Selection Criteria: LEAST ENERGY 

Literature

Structure and RNA Recognition by the Snrna and Snorna Transport Factor Phax.

Mourao, A., Varrot, A., Mackereth, C.D., Cusack, S., Sattler, M.

(2010) RNA 16: 1205

• PubMed: 20430857 
• DOI: https://doi.org/10.1261/rna.2009910
• Primary Citation of Related Structures:  
  2W4S, 2XC7


• PubMed Abstract: 
  

Small nuclear and small nucleolar RNAs (snRNAs and snoRNAs) are critical components of snRNPs and snoRNPs and play an essential role in the maturation of, respectively, mRNAs and rRNAs within the nucleus of eukaryotic cells. Complex and specific pathways exist for the assembly of snRNPs and snoRNPs, involving, for instance, nucleocytoplasmic transport of snRNAs and intranuclear transport between compartments of snoRNAs. The phosphorylated adaptor for nuclear export (PHAX) is required for nuclear export of snRNAs in metazoans and also involved in the intranuclear transport of snoRNAs to Cajal bodies. PHAX contains a conserved single-stranded nucleic acid binding domain (RNA_GG_bind domain) with no sequence homology with any other known RNA-binding module. Here, we report NMR and X-ray crystallography studies that elucidate the structural basis for RNA recognition by the PHAX RNA-binding domain (PHAX-RBD). The crystal structure of the RNA_GG_bind domain from the parasite Cryptosporidium parvum (Cp RBD) forms well-folded dimers in solution in the absence of any ligand. The human PHAX-RBD is monomeric and only adopts a tertiary fold upon RNA binding. The PHAX-RBD represents a novel helical fold and binds single-stranded RNA with micromolar affinity without sequence specificity. RNA recognition by human PHAX-RBD is consistent with mutational analysis that affects RNA binding and PHAX-mediated nuclear export. Our data suggest that the PHAX-RBD mediates auxiliary RNA contacts with the snRNA and snoRNA substrates that are required for transport and/or substrate release.

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Organizational Affiliation: 

Institute of Structural Biology, Helmholtz Zentrum München, 85764 Neuherberg, Germany.

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
PHOSPHORYLATED ADAPTER RNA EXPORT PROTEIN	A	104	Homo sapiens	Mutation(s): 0  Gene Names: PHAX, RNUXA
UniProt & NIH Common Fund Data Resources
Find proteins for Q9H814 (Homo sapiens) Explore Q9H814  Go to UniProtKB:  Q9H814
PHAROS:  Q9H814

Entity ID: 2
Molecule	Chains	Length	Organism	Image
5'-(AP*UP*CP*GP)-3'	B [auth P]	4	N/A

Experimental Data & Validation

Experimental Data

• Method: SOLUTION NMR
• Conformers Calculated: 100 
• Conformers Submitted: 10 
• Selection Criteria: LEAST ENERGY 

Structure Validation

Entry History 

Deposition Data

• Released Date: 2010-04-28 
Deposition Author(s): Mourao, A., Mackereth, C.D., Varrot, A., Cusack, S., Sattler, M.

Revision History  

• Version 1.0: 2010-04-28
  Type: Initial release
  
• Version 1.1: 2011-05-08
  Changes: Version format compliance
• Version 1.2: 2011-07-13
  Changes: Version format compliance