Enzyme of the plastid non-mevalonate pathway for isoprenoid biosynthesis that catalyzes the phosphorylation of the position 2 hydroxy group of 4-diphosphocytidyl-2C-methyl-D-erythritol. Is essential for chloroplast development. 4-CDP-2-C-methyl-D-erythritol + ATP = 4-CDP-2-C-methyl-D-erythritol 2-phosphate + ADP + H(+) Isoprenoid biosynthesis; isopentenyl diphosphate biosynthesis via DXP pathway; isopentenyl diphosphate from 1-deoxy-D-xylulose 5-phosphate: step 3/6. Expressed in leaves, stems, flowers and siliques. Circadian-regulated with a peak in the late period of the light phase. Albino phenotype and seedling lethal when homozygous. The phenotype is caused by an early arrest in chloroplast differentiation. Belongs to the GHMP kinase family. IspE subfamily.