19  structures 0  species 0  sequences

Clan: U1 (CL00005)


U1 clan

The U1 clan contains the RNA families U1, U1_yeast and U11. Homology between these families has been established in the published literature [1-4].

This clan contains 4 families and the total number of sequence regions in the clan is 12,315.

Literature references

  1. Yu YT, Tarn WY, Yario TA, Steitz JA, Exp Cell Res. 1996;229:276-81.: More Sm snRNAs from vertebrate cells. 8986610
  2. Tarn WY, Steitz JA, Trends Biochem Sci 1997;22:132-137.: Pre-mRNA splicing: the discovery of a new spliceosome doubles the challenge. 9149533
  3. Zwieb C, Nucleic Acids Res. 1996;24:76-9.: The uRNA database. 8594606
  4. Zwieb C, Nucleic Acids Res 1997;25:102-103.: The uRNA database. 9016512


This clan contains the following 4 member families:

U1 U1_yeast U11 Gl_U1

External database links


For those sequences which have a structure in the Protein DataBank, we generate a mapping between EMBL, PDB and Rfam coordinate systems. The table below shows the mapping between the Rfam families in this clan, the corresponding EMBL entries, and the region of the three-dimensional structures that are available for that sequence.

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Secondary structures

This tool allows you to view the secondary structure images of two clan members side-by-side. Choose the family structures using the two drop-down menus below.


The table below shows the number of occurrences of each family throughout the sequence database. In brackets beside each number is the percentage of the total number of sequence hits for the clan that are represented by this family. The rightmost column provides a link to the alignments tab for each family.

Rfam family Num. regions Alignment
Gl_U1 (RF02491) 2 (0.0%) View
U11 (RF00548) 682 (5.5%) View
U1_yeast (RF00488) 35 (0.3%) View
U1 (RF00003) 11,596 (94.2%) View