Crystal structure of an engrailed homeodomain-DNA complex at 2.8 Å resolution: A framework for understanding homeodomain-DNA interactions

The highest affinity DNA element bound by Pbx complexes in t(1;19) leukemic cells fails to mediate cooperative DNA-binding or cooperative transactivation by E2a-Pbx1 and Class I Hox proteins – evidence for selective targetting of E2a-Pbx1 to a subset of Pbx-recognition elements

“…The Pbx-NFPP complex was further distinct in its recognition of a variant motif in which the third A in the NFPP binding core, which is essential for Pbx-Hox binding to TGATTGAT and which binds the invariant Asn 51 in the Hox HD, could be altered to G without appreciable loss of complex formation. The fact that a hydrogen bond between Asp51 of Hox HDs and this adenine is essential for binding of Hox proteins to their DNA targets suggests that NFPP may not be a HD protein (Desplan et al, 1988;Kissinger et al, 1990;Laughon, 1991;Gehring et al, 1994). NFPP was also distinct from Class I Hox proteins in its failure to form heterodimers with endogenous E2a-Pbx1, even though E2a-Pbx1 was active as demonstrated by its ability to heterodimerize with exogenous HoxA5 on a PRS.…”

Cellular proliferation and transformation induced by HOXB4 and HOXB3 proteins involves cooperation with PBX1

“…B4-3, Figure 5) decreased the transforming potential of mutant protein ®vefold when compared to the wild type HOXB4 (Figure 5). To disrupt the homeodomain/DNA interactions without compromising the conformation of HOXB4 protein we substituted the highly conserved asparagine-51 within helix three of the homeodomain, reported to represent a direct contact point between the homeodomains and the target DNA sequences (Kissinger et al, 1990;Wolberger et al, 1991), with alanine (mutant no. B4-4, Figure 5).…”

Drosophilaengrailed‐1, 10‐phenanthroline chimeras as probes of homeodomain‐DNA complexes

“…6B). arm and the minor groove of DNA, we wanted to determine the The DNA scission pattern of the two derivatives that showed overall orientaEion of the homeodomain relative to its specific significant DNA cutting supports the co-crystal structure of the Sequence 1 has been used by Kissinger et al (1990) in the co-crystallization experiments with the homeodomain. Sequence 4 has been identified by E28C-A-OP.…”

“…Several structural models of homeodomain-DNA complexes have been determined. X-ray crystal structures of Drosophila engrailed (Kissinger et al, 1990), yeast MAT a 2 (Wolberger et al, 1991), and mammalian Oct-1 (Klemm et al, 1994) homeodomains bound to DNA and an NMR structure of the Drosophila Antennapedia homeodomain-DNA complex (Otting et al, 1990) were very similar. These structures revealed an N-terminal arm that makes contacts with the first two bases of the consensus 5'-TAATNN-3' sequence in the minor groove and a core region of three a-helices, in which one of the helices interacts with the last four bases of the consensus sequence in the major groove.…”