title: Arabidopsis proteins containing similarity to the universal stress protein domain of bacteria.
abstract: We have collected a set of 44 Arabidopsis proteins with similarity to the USPA (universal stress protein A of Escherichia coli) domain of bacteria. The USPA domain is found either in small proteins, or it makes up the N-terminal portion of a larger protein, usually a protein kinase. Phylogenetic tree analysis based upon a multiple sequence alignment of the USPA domains shows that these domains of protein kinases 1.3.1 and 1.3.2 form distinct groups, as do the protein kinases 1.4.1. This indicates that their USPA domain structures have diverged appreciably and suggests that they may subserve distinct cellular functions. Two USPA fold classes have been proposed: one based on Methanococcus jannaschii MJ0577 (1MJH) that binds ATP, and the other based on the Haemophilus influenzae universal stress protein (1JMV), highly similar to E. coli UspA, which does not bind ATP. A set of common residues involved in ATP binding in 1MJH and conserved in similar bacterial sequences is also found in a distinct cluster of Arabidopsis sequences. Threading analysis, which examines aspects of secondary and tertiary structure, confirms this Arabidopsis sequence cluster as highly similar to 1MJH. This structural approach can distinguish between the characteristic fold differences of 1MJH-like and 1JMV-like bacterial proteins and was used to assign the complete set of candidate Arabidopsis proteins to one of these fold classes. It is clear that all the plant sequences have arisen from a 1MJH-like ancestor.
authors.affiliation: Department of Biology, Point Loma Nazarene University, 3900 Lomaland Drive, San Diego, California 92106, USA. dkerk@ptloma.edu
authors.forename: David
authors.initials: D
authors.lastname: Kerk
authors.forename: Joshua
authors.initials: J
authors.lastname: Bulgrien
authors.forename: Douglas W
authors.initials: DW
authors.lastname: Smith
authors.forename: Michael
authors.initials: M
authors.lastname: Gribskov
mesh_terms: D000255:Adenosine Triphosphate / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000378:metabolism; D006193:Haemophilus influenzae / Q000378:metabolism; D006360:Heat-Shock Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D017017:Methanococcus / Q000378:metabolism; D010802:Phylogeny; D011487:Protein Conformation; D017510:Protein Folding; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D001426:Bacterial Proteins; D002352:Carrier Proteins; D006360:Heat-Shock Proteins; C078564:universal stress protein A, Bacteria; D000255:Adenosine Triphosphate; D011494:Protein Kinases