37 

 phosphatase -linked goat -anti -rabbit antibody for 1 h, and 

 then incubated in STP buffer containing MgClj and 

 substrates, nitroblue tetrazolium and the p-toluidine salt 

 of 5-bromo-4-chloro-3-indolyl phosphate. After 1 h, 

 membranes were viewed and photographed. 



Antibody precipitation of DOT and SDH from C. sorokiniana 

 Antibody made to SP-I was incubated 1:1, 2:1, or 4:1 

 with Chlorella extract (controls included preimmune 

 antiserum and extract diluted with buffer) . After 10 min at 

 37°C, and centrifugation for 5 min at full speed in a 

 microfuge, preparations were assayed under standard 

 conditions for SDH and DQT activities. 



cDNA cloning and sequencing 

 Tobacco leaf cDNA library 



A cDNA library prepared from Nicotiana tabacum var. 

 SRI tissue culture cells, inserted into pBluescript SK- 

 plasmids and packaged into Lambda ZAP II vectors, was 

 purchased from Stratagene, La Jolla, CA. E. coli XLl-Blue 

 (a host strain used for immunological screening of libraries 

 constructed in Lambda ZAP expression vectors) and E. coli 

 SOLR (a non- suppressing host strain for use after excision 

 of the pBluescript plasmid from the Lambda Zap vector) were 

 included. Helper phage, ExAssist, efficient for in vivo 

 excision of the plasmid from the Lambda Zap vector without 

 replication of the phage genome was also included. 



