| Autor: |
Nichols, C.E., Johnson, C., Lockyer, M., Charles, I.G., Lamb, H.K., Hawkins, A.R., Stammers, D.K. |
| Zdroj: |
Proteins; Jul2006, Vol. 64 Issue 1, p111-123, 13p |
| Abstrakt: |
The Salmonella typhimurium ' yeaZ' gene ( StyeaZ) encodes an essential protein of unknown function ( StYeaZ), which has previously been annotated as a putative homolog of the Pasteurella haemolytica M22 O-sialoglycoprotein endopeptidase Gcp. YeaZ has also recently been reported as the first example of an RPF from a gram-negative bacterial species. To further characterize the properties of StYeaZ and the widely occurring MK-M22 family, we describe the purification, biochemical analysis, crystallization, and structure determination of StYeaZ. The crystal structure of StYeaZ reveals a classic two-lobed actin-like fold with structural features consistent with nucleotide binding. However, microcalorimetry experiments indicated that StYeaZ neither binds polyphosphates nor a wide range of nucleotides. Additionally, biochemical assays show that YeaZ is not an active O-sialoglycoprotein endopeptidase, consistent with the lack of the critical zinc binding motif. We present a detailed comparison of YeaZ with available structural homologs, the first reported structural analysis of an MK-M22 family member. The analysis indicates that StYeaZ has an unusual orientation of the A and B lobes which may require substantial relative movement or interaction with a partner protein in order to bind ligands. Comparison of the fold of YeaZ with that of a known RPF domain from a gram-positive species shows significant structural differences and therefore potentially distinctive RPF mechanisms for these two bacterial classes. Proteins 2006. © 2006 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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