1r95

Publication Abstract from PubMed

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.

Crystal structure of the ancient, Fe-S scaffold IscA reveals a novel protein fold.,Bilder PW, Ding H, Newcomer ME Biochemistry. 2004 Jan 13;43(1):133-9. PMID:14705938^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.