1R94

Crystal Structure of IscA (MERCURY DERIVATIVE)

Summary for 1R94

• Entry DOI: 10.2210/pdb1r94/pdb
• Related: 1R95
• Descriptor: Protein yfhF, MERCURY (II) ION (3 entities in total)
• Functional Keywords: tetrameric, beta barrel, iron-sulfur cluster protein, pseudo-symmetric motifs, metal transport
• Biological source: Escherichia coli
• Total number of polymer chains: 2
• Total formula weight: 26088.06

Authors

Bilder, P.W.,Ding, H.,Newcomer, M.E. (deposition date: 2003-10-28, release date: 2003-12-23, Last modification date: 2024-02-14)

Primary citation

Bilder, P.W.,Ding, H.,Newcomer, M.E.
Crystal structure of the ancient, Fe-S scaffold IscA reveals a novel protein fold.
Biochemistry, 43:133-139, 2004

PubMed Abstract: IscA belongs to an ancient family of proteins responsible for iron-sulfur cluster assembly in essential metabolic pathways preserved throughout evolution. We report here the 2.3 A resolution crystal structure of Escherichia coli IscA, a novel fold in which mixed beta-sheets form a compact alpha-beta sandwich domain. In contrast to the highly mobile secondary structural elements within the bacterial Fe-S scaffold protein IscU, a protein which is thought to have a similar function, the great majority of the amino acids that are conserved in IscA homologues are located in elements that constitute a well-ordered fold. However, the 10-residue C-terminal tail segment that contains two invariant cysteines critical for the Fe-S-binding function of a cyanobacterial (Synechocystis PCC) IscA homologue is not ordered in our structure. In addition, the crystal packing reveals a helical assembly that is constructed from two possible tetrameric oligomers of IscA.

PubMed: 14705938

Experimental method

X-RAY DIFFRACTION (2.3 Å)