1LFB

THE X-RAY STRUCTURE OF AN ATYPICAL HOMEODOMAIN PRESENT IN THE RAT LIVER TRANSCRIPTION FACTOR LFB1(SLASH)HNF1 AND IMPLICATIONS FOR DNA BINDING

Summary for 1LFB

• Entry DOI: 10.2210/pdb1lfb/pdb
• Descriptor: LIVER TRANSCRIPTION FACTOR (LFB1) (1 entity in total)
• Functional Keywords: transcription regulation
• Biological source: Rattus norvegicus (Norway rat)
• Cellular location: Nucleus: P22361
• Total number of polymer chains: 1
• Total formula weight: 11677.20

Authors

Ceska, T.A.,Lamers, M.,Monaci, P.,Nicosia, A.,Cortese, R.,Suck, D. (deposition date: 1993-06-28, release date: 1993-10-31, Last modification date: 2024-02-14)

Primary citation

Ceska, T.A.,Lamers, M.,Monaci, P.,Nicosia, A.,Cortese, R.,Suck, D.
The X-ray structure of an atypical homeodomain present in the rat liver transcription factor LFB1/HNF1 and implications for DNA binding.
EMBO J., 12:1805-1810, 1993

PubMed Abstract: The transcription factor LFB1/HNF1 from rat liver nuclei is a 628 amino acid protein that functions as a dimer binding to the inverted palindrome GTTAATN-ATTAAC consensus site. We have crystallized a 99 residue protein containing the homeodomain portion of LFB1, and solved its structure using X-ray diffraction data to 2.8 A resolution. The topology and orientation of the helices is essentially the same as that found in the engrailed, MAT alpha 2 and Antennapedia homeodomains, even though the LFB1 homeodomain contains 21 more residues. The 21 residue insertion is found in an extension of helix 2 and consequent lengthening of the connecting loop between helix 2 and helix 3. Comparison with the engrailed homeodomain-DNA complex indicates that the mode of interaction with DNA is similar in both proteins, with a number of conserved contacts in the major groove. The extra 21 residues of the LFB1 homeodomain are not involved in DNA binding. Binding of the LFB1 dimer to a B-DNA palindromic consensus sequence requires either a conformational change of the DNA (presumably bending), or a rearrangement of the subunits relative to the DNA.

PubMed: 8491173

Experimental method

X-RAY DIFFRACTION (2.8 Å)