1. KLINTWORTH, R., HUSEMANN, M., SALNIKOW, J. AND BOWIEN, B.
Chromosomal and plasmid locations for phosphoribulokinase genes in
J.BACTERIOL. 164 954-956 (1985).
2. GIBSON, J.L., CHEN, J.H., TOWER, P.A. AND TABITA, F.R.
The form II fructose-1,6-bisphosphatase and phosphoribulokinase genes form
part of a large operon in Rhobacter sphaeroides: primary structure and
insertional mutagenesis analysis.
BIOCHEMISTRY 29 8085-8093 (1990).
3. POTER, M.A., STRINGER, C.D. AND HARTMAN, F.C.
Characterization of the regulatory thioredoxin site of phosphoribulokinase.
J.BIOL.CHEM. 263 123-129 (1988).
Phosphoribulokinase (PRK) catalyses the ATP-dependent phosphorylation of
ribulose-5-phosphate to ribulose-1,5-phosphate, a key step in the pentose
phosphate pathway [1-3], where carbon dioxide is assimilated by
autotrophic organisms . In general, plant enzymes are light-activated
by the thioredoxin/ferredoxin system, while those from photosynthetic
bacteria are regulated by a system that has an absolute requirement for
NADH . Thioredoxin/ferredoxin regulation is mediated by the reversible
oxidation/reduction of sulphydryl and disulphide groups. In the spinach
enzyme (KPPR_SPIOL) , the participating residues are Cys-16 and Cys-55.
Sequence analysis shows the first of these cysteines to be present in the
ATP-binding site ; neither is found in the bacterial sequences.
PHRIBLKINASE is a 4-element fingerprint that provides a signature for
phosphoribulokinases. The fingerprint was derived from an initial alignment
of 8 sequences: the motifs were drawn from conserved regions spanning the
N-terminal half of the alignment - motif 1 contains a putative ATP-binding
site, and motif 3 includes the region encoded by PROSITE pattern
PHOSPHORIBULOKINASE (PS00567). Two iterations on OWL27.0 were required to
reach convergence, at which point a true set comprising 17 sequences was
identified. A single partial match (URK_HAEIN) was also found, a uridine
kinase that shows slight similarity to motifs 3 and 4.
An update on SPTR37_9f identified a true set of 15 sequences.