Purified recombinant Arabidopsis HSP21 is a large
homo-oligomer. A, Coomassie blue-stained SDS-PAGE of recombinant HSP21
before and after purification. Lane 1, Lysate of E. coli
cells expressing HSP21; lane 2, purified HSP21. B, Recombinant
Arabidopsis HSP21 forms a 300-kD complex that comigrates with HSP21
from an E. coli lysate. Lane 1, Lysate of E.
coli cells that do not express HSP21 (−); lane 2, lysate of
E. coli cells expressing HSP21 (+); and lane 3,
assembled HSP21 after purification (Pure) (indicated by arrowhead).
Samples were separated by N-PAGE and the gel was stained with Coomassie
blue. Numbers at left indicate molecular mass standards (in
kilodaltons).