. Jalciparum cultures were maintained as described previously (Trager and Jensen, 1976). Briefly, P. Jalciparum strain 3D7 was cultured at 37°C in RPMI " 1640 medium (list I) in 0+ RBCs supplemented with 10% AB+ human serum or : 0.5% Albumax II (complete medium). All media were preheated to 37°C and care was taken to minimize the handling time outside the 37°C incubator. Cultures were gassed with 5% CO2, 3% O2, and 92% N2 for 20 seconds and maintained at 37°C.

Oligonucleotides used in this study were synthesized by Rama Biotechnologies (Hyderabad, India).

Ampicillin, tetracycline, chloramphenicol and gentamycin were from Sigma. Geniticin ( G418 ) was from Gibco Laboratories, USA.

DNA restriction enzymes were purchased from New England Biolabs (Massachusetts, USA) and Promega Corporation, (Madison, U.S.A.). RNase A was obtained from Qiagen (West Sussex, U.K.). DNA ligase, RNA polymerase, RNAsin, Taq DNA polymerase, T7 RNA polymerase, SP6 RNA Polymerase and alkaline phosphatase were obtained from Promega Biotech.

EDTA 2 mMThis was prepared at 50X concentration and used at 1X concentration. Both TBE and TAE were used as standard electrophoresis buffers.Gel loading buffer with dye Tris-Cl (pH 7.5) 250 mM Bromophenol blue/ Xylene cyanol 0.02% Glycerol 20%INOUE (PIPES) Buffer PIPES (Free acid) 10 mM CaCl2.2H2O 15 mM KCl 250 mM MnCl2.4H2O 55 mM pHwas adjusted to 6.7 with 1N KOH. PIPES gets into solution when the pH is greater than 6.7. MnCl2 was dissolved separately and added with stirring. The pH was then adjusted to 6.7 and solution wasfilter sterilized and stored at –20ºC.Z Buffer (for β-galactosidase assay) Na2HPO416.1 g NaH2PO45.5 g KCl 0.75 gMgSO4.7H2O 0.246 g H2O to 1000 ml pH was adjusted to 7.0 and stored at 4ºC.Pre-Hybridization Buffer 20X Saline-sodium citrate (SSC)3ml50% dextran sulphate2ml50X Denhardt’s solution1m

20%SDS250 μl10 mg/ml Salmon sperm DNA100 μlDEPC waterto 10mlHybridization Buffer Same as pre-hybridisation buffer but contains the radio-labelled probe.SDS sampleBuffer(1X)Tris-HCl, pH 6.850mMGlycerol10%EDTA12.5 mM SDS2%Bromophenol blue0.02%β-mercaptoethanol1%Running buffer for western blottingGlycine14.4 g/lTris base3.05 g/lSDS1.0 g/lTransfer buffer for western blottingGlycine14.4 g/lTris base3.03 g/lThe above salts were dissolved in 800 ml of milliQ water and 200 ml of methanol was then added. The buffer was chilled before use.TBST buffer for Western blot10X of TBS (1000ml)Sodium chloride80 gPotassium chloride2 gDisodium hydrogen phosphate(Na2HPO4)14.1 gPotassium dihydrogen phosphate(KH2PO4)2.49 gMilliQ waterto 1000m

EDTA 2 mMThis was prepared at 50X concentration and used at 1X concentration. Both TBE and TAE were used as standard electrophoresis buffers.Gel loading buffer with dye Tris-Cl (pH 7.5) 250 mM Bromophenol blue/ Xylene cyanol 0.02% Glycerol 20%INOUE (PIPES) Buffer PIPES (Free acid) 10 mM CaCl2.2H2O 15 mM KCl 250 mM MnCl2.4H2O 55 mM pHwas adjusted to 6.7 with 1N KOH. PIPES gets into solution when the pH is greater than 6.7. MnCl2 was dissolved separately and added with stirring. The pH was then adjusted to 6.7 and solution wasfilter sterilized and stored at –20ºC.Z Buffer (for β-galactosidase assay) Na2HPO416.1 g NaH2PO45.5 g KCl 0.75 gMgSO4.7H2O 0.246 g H2O to 1000 ml pH was adjusted to 7.0 and stored at 4ºC.Pre-Hybridization Buffer 20X Saline-sodium citrate (SSC)3ml50% dextran sulphate2ml50X Denhardt’s solution1ml

20%SDS250 μl10 mg/ml Salmon sperm DNA100 μlDEPC waterto 10mlHybridization Buffer Same as pre-hybridisation buffer but contains the radio-labelled probe.SDS sampleBuffer(1X)Tris-HCl, pH 6.850mMGlycerol10%EDTA12.5 mM SDS2%Bromophenol blue0.02%β-mercaptoethanol1%Running buffer for western blottingGlycine14.4 g/lTris base3.05 g/lSDS1.0 g/lTransfer buffer for western blottingGlycine14.4 g/lTris base3.03 g/lThe above salts were dissolved in 800 ml of milliQ water and 200 ml of methanol was then added. The buffer was chilled before use.TBST buffer for Western blot10X of TBS (1000ml)Sodium chloride80 gPotassium chloride2 gDisodium hydrogen phosphate(Na2HPO4)14.1 gPotassium dihydrogen phosphate(KH2PO4)2.49 gMilliQ waterto 1000ml

1litreof 1X TBS +1 ml of Tween-2040% Acrylamide solution (29:1) Acrylamide39 g Bis-acrylamide 1 g H2O to 100 ml7.5M Urea 10%acrylamidecomposition 40% Acrylamide 12.5mlUrea22.5g5X TBE 10ml DEPC treated H2O to 50ml The gel mixtures were filtered through a 0.45 μ Millipore filter before adding APS and TEMED

Citrate Buffer Citric Acid (0.1 M) 4.7 volumesSodium citrate (0.1 M)15.4 volumesTE Buffer Tris-Cl (pH 8.0) 10 mM EDTA 1 mMTBE Buffer Tris-Borate 90 mM EDTA 2 mMThis was prepared as 5X solution and used at 0.5X concentration.TAE Buffer Tris-Acetate 40 mM