3DU1
The 2.0 Angstrom Resolution Crystal Structure of HetL, a Pentapeptide Repeat Protein involved in Heterocyst Differentiation Regulation from the Cyanobacterium Nostoc sp. Strain PCC 7120
Summary for 3DU1
| Entry DOI | 10.2210/pdb3du1/pdb |
| Descriptor | All3740 protein (2 entities in total) |
| Functional Keywords | right-handed beta helix, repeated five residue fold, pentapeptide repeat protein, structural protein |
| Biological source | Nostoc sp. |
| Total number of polymer chains | 1 |
| Total formula weight | 27778.27 |
| Authors | Kennedy, M.A.,Ni, S.,Sheldrick, G.M. (deposition date: 2008-07-16, release date: 2008-11-11, Last modification date: 2024-03-20) |
| Primary citation | Ni, S.,Sheldrick, G.M.,Benning, M.M.,Kennedy, M.A. The 2A resolution crystal structure of HetL, a pentapeptide repeat protein involved in regulation of heterocyst differentiation in the cyanobacterium Nostoc sp. strain PCC 7120 J.Struct.Biol., 165:47-52, 2008 Cited by PubMed Abstract: The hetL gene from the cyanobacterium Nostoc sp. PCC 7120 encodes a 237 amino acid protein (25.6kDa) containing 40 predicted tandem pentapeptide repeats. Nostoc sp. PCC 7120 is a filamentous cyanobacterium that forms heterocysts, specialized cells capable of fixing atmospheric N(2) during nitrogen starvation in its aqueous environment. Under these conditions, heterocysts occur in a regular pattern of approximately one out of every 10-15 vegetative cells. Heterocyst differentiation is highly regulated involving hundreds of genes, one of which encodes PatS, thought to be an intercellular peptide signal made by developing heterocysts to inhibit heterocyst differentiation in neighboring vegetative cells, thus contributing to pattern formation and spacing of heterocysts along the filament. While overexpression of PatS suppresses heterocyst differentiation in Nostoc sp. PCC 7120, overexpression of HetL produces a multiple contiguous heterocyst phenotype with loss of the wild type heterocyst pattern, and strains containing extra copies of hetL allow heterocyst formation even in cells overexpressing PatS. Thus, HetL appears to interfere with heterocyst differentiation inhibition by PatS, however, the mechanism for HetL function remains unknown. As a first step towards exploring the mechanism for its biochemical function, the crystal structure of HetL has been solved at 2.0A resolution using sulfur anomalous scattering. PubMed: 18952182DOI: 10.1016/j.jsb.2008.09.010 PDB entries with the same primary citation |
| Experimental method | X-RAY DIFFRACTION (2 Å) |
Structure validation
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