TY - JOUR
T1 - APS kinase from Arabidopsis thaliana
T2 - Genomic organization, expression, and kinetic analysis of the recombinant enzyme
AU - Lee, Sangman
AU - Leustek, Thomas
N1 - Funding Information:
Funded by the National Science Foundation IBN-9601145. The cDNA and genomic DNA sequences reported in this paper have been submitted to GenBank and have been assigned the accession numbers U05238 and U59759.
PY - 1998/6/9
Y1 - 1998/6/9
N2 - The gene encoding 5'-adenylylsulfate (APS) kinase (EC 2.7.1.25) (APK) was cloned from Arabidopsis thaliana. There is a single APK locus in A. thaliana. The coding sequence of the gene is composed of 7 exons, interrupted by 6 introns. A transcriptional initiation site was detected 120 bp 5' of the initiation codon. APK mRNA is slightly more abundant in leaves than in roots of A. thaliana and its level does not change in response to sulfur starvation. The APK protein, synthesized in vitro, is able to enter isolated intact chloroplasts. Recombinant APS kinase shows maximal activity at 10 μM APS with 5 mM ATP, but it is inhibited at APS concentrations above 10 μM. The inhibition is alleviated at higher ATP concentrations. Reciprocal plot analysis showed that the theoretical V(max) is ~ 1.2 μmol min-1 mg-1 at 25°C, pH 8.0; the K(m) values are 3.6 μM APS and 1.8 mM ATP.
AB - The gene encoding 5'-adenylylsulfate (APS) kinase (EC 2.7.1.25) (APK) was cloned from Arabidopsis thaliana. There is a single APK locus in A. thaliana. The coding sequence of the gene is composed of 7 exons, interrupted by 6 introns. A transcriptional initiation site was detected 120 bp 5' of the initiation codon. APK mRNA is slightly more abundant in leaves than in roots of A. thaliana and its level does not change in response to sulfur starvation. The APK protein, synthesized in vitro, is able to enter isolated intact chloroplasts. Recombinant APS kinase shows maximal activity at 10 μM APS with 5 mM ATP, but it is inhibited at APS concentrations above 10 μM. The inhibition is alleviated at higher ATP concentrations. Reciprocal plot analysis showed that the theoretical V(max) is ~ 1.2 μmol min-1 mg-1 at 25°C, pH 8.0; the K(m) values are 3.6 μM APS and 1.8 mM ATP.
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U2 - 10.1006/bbrc.1998.8751
DO - 10.1006/bbrc.1998.8751
M3 - Article
C2 - 9636674
AN - SCOPUS:0032499604
SN - 0006-291X
VL - 247
SP - 171
EP - 175
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 1
ER -