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* Chaperonins TCP-1 signatures *
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The TCP-1 protein [1,2] (Tailless Complex Polypeptide 1)  was first identified
in mice  where  it  is especially  abundant  in testis but present in all cell
types. It has  since  been  found  and  characterized  in many other mammalian
species, in Drosophila and in yeast.  TCP-1  is  a highly conserved protein of
about 60  Kd  (556  to 560 residues) which participates in a hetero-oligomeric
900 Kd  double-torus shaped particle [3] with 6 to 8 other different subunits.
These subunits,  the  chaperonin  containing  TCP-1 (CCT) subunit beta, gamma,
delta, epsilon, zeta and eta are evolutionary related to TCP-1 itself [4]. The
CCT is  known  to act as a molecular chaperone for tubulin, actin and probably
some other proteins.

The CCT  subunits  are  highly  related  to  TF55  [5],  a molecular chaperone
isolated from   the  archaebacterium  Sulfolobus  shibatae.  TF55  has  ATPase
activity, is known to bind unfolded polypeptides and forms an  homo-oligomeric
complex of two stacked nine-membered rings.

The TCP-1 family of proteins are weakly, but significantly [6], related to the
cpn60/groEL chaperonin family.

As signature patterns of this family of chaperonins,  we chose three conserved
regions located in the N-terminal domain.

-Consensus pattern: [RK]-[ST]-x-[LFY]-G-P-x-[GS]-x-x-K-[LIVM]
-Sequence known to belong to this class detected by the pattern: ALL
-Other sequence(s) detected in SWISS-PROT: NONE.

-Consensus pattern: [LIVM]-[TS]-[NK]-D-G-[AN]-[TAV]-[LIVM]-L
-Sequence known to belong to this class detected by the pattern: ALL
-Other sequence(s) detected in SWISS-PROT: NONE.

-Consensus pattern: Q-[DE]-x-x-[LIVTA]-[GA]-D-G-T
-Sequence known to belong to this class detected by the pattern: ALL
-Other sequence(s) detected in SWISS-PROT: yeast hypothetical protein YKL059c

-Expert(s) to contact by email: Willison K.R.
                                willison@icr.ac.uk

-Last update: June 1994 / Patterns and text revised.

[ 1] Ellis J.
     Nature 358:191-192(1992).
[ 2] Nelson R.J., Craig E.A.
     Curr. Biol. 2:487-489(1992).
[ 3] Lewis V.A., Hynes G.M., Zheng D., Saibil H., Willison K.R.
     Nature 358:249-252(1992).
[ 4] Kubota H., Hynes G., Carne A., Ashworth A., Willison K.R.
     Curr. Biol. 4:89-99(1994)
[ 5] Trent J.D., Nimmesgern E., Wall J.S., Hartl F.U., Horwich A.L.
     Nature 354:490-493(1991).
[ 6] Hemmingsen S.M.
     Nature 357:650-650(1992).