P26olf (P26)
entry list
alignment
P26olf (P26) was prepared from the olfactory epithelium of Rana
catesberiana [55]. P26 has 217 residues. The two putative EF-hands
in the first half of P26 are most similar to the two in the second
half; as in TCBP this reflects a recent gene duplication. EF-hand 3 is
separated from EF-hand 2 by 36 residues that are 60% identical to the
C-terminal twenty residues of a rabbitt S100. The expectation value of
0.97 indicates that the alignment is not significant for the entire
database but this similarity with another EF-hand protein is
interesting. None of the EF-hands are inferred to bind calcium in
canonical conformation. However, P26 is purified by elution from
phenyl Sepharose (following initial binding in 1.0 mM [Ca2+]) with
EGTA. It is possible that domains 1 and 3 have an unconventional
coordination as found in domains 1 of S100, ICBP, and HYFL.