TY - JOUR
T1 - Secondary structure switching in Cro protein evolution
AU - Newlove, Tracey
AU - Konieczka, Jay H.
AU - Cordes, Matthew H.J.
PY - 2004/4
Y1 - 2004/4
N2 - We report the solution structure of the Cro protein from bacteriophage P22. Comparisons of its sequence and structure to those of λ Cro strongly suggest an α-to-β secondary structure switching event during Cro evolution. The folds of P22 Cro and λ Cro share a three α helix fragment comprising the N-terminal half of the domain. However, P22 Cro's C terminus folds as two helices, while λ Cro's folds as a β hairpin. The all-α fold found for P22 Cro appears to be ancestral, since it also occurs in cI proteins, which are anciently duplicated paralogues of Cro. PSI-BLAST and transitive homology analyses strongly suggest that the sequences of P22 Cro and λ Cro are globally homologous despite encoding different folds. The α+β fold of λ Cro therefore likely evolved from its all-α ancestor by homologous secondary structure switching, rather than by nonhomologous replacement of both sequence and structure.
AB - We report the solution structure of the Cro protein from bacteriophage P22. Comparisons of its sequence and structure to those of λ Cro strongly suggest an α-to-β secondary structure switching event during Cro evolution. The folds of P22 Cro and λ Cro share a three α helix fragment comprising the N-terminal half of the domain. However, P22 Cro's C terminus folds as two helices, while λ Cro's folds as a β hairpin. The all-α fold found for P22 Cro appears to be ancestral, since it also occurs in cI proteins, which are anciently duplicated paralogues of Cro. PSI-BLAST and transitive homology analyses strongly suggest that the sequences of P22 Cro and λ Cro are globally homologous despite encoding different folds. The α+β fold of λ Cro therefore likely evolved from its all-α ancestor by homologous secondary structure switching, rather than by nonhomologous replacement of both sequence and structure.
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U2 - 10.1016/j.str.2004.02.024
DO - 10.1016/j.str.2004.02.024
M3 - Article
C2 - 15062080
AN - SCOPUS:1842607238
VL - 12
SP - 569
EP - 581
JO - Structure with Folding & design
JF - Structure with Folding & design
SN - 0969-2126
IS - 4
ER -