*** For details on how to be removed from this list visit the *** *** CCP4 home page http://www.ccp4.ac.uk ***
Hi, A quick note - not ALL proteins in E. coli and other bacteria have their initiator Met removed. In fact, the removal of the initiator Met is dependent on the second (and to lesser extent, third) amino-acid of the sequence. If your second amino-acid is small (G,A,S,P) then the initiator Met is very likely to be removed (the active site channel of methionine aminopeptidase does not accommodate large amino-acids all too well). With other amino acids processing may be impaired or even completely abolished. Artem -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Tuesday, September 26, 2006 12:19 PM To: Yadong Yu Cc: ccp4bb Subject: Re: [ccp4bb]: initial methionine lost *** For details on how to be removed from this list visit the *** *** CCP4 home page http://www.ccp4.ac.uk *** [EMAIL PROTECTED] wrote on 09/26/2006 11:47:47 AM: > Hi, > (snip) > > Anyone experienced such problem? Is the head of protein already cut > during expression, or just lost in MALDI experiments? > > Yadong Yu Dear Yaodong - All (?) E. coli expressed proteins have their initial methionine removed during translation by methionine aminopeptidase. This is no doubt what you're seeing. - Matt -- Matthew Franklin phone:(917)606-4116 Senior Scientist, ImClone Systems fax:(212)645-2054 180 Varick Street, 6th floor New York, NY 10014 Confidentiality Note: This e-mail, and any attachment to it, contains privileged and confidential information intended only for the use of the individual(s) or entity named on the e-mail. If the reader of this e-mail is not the intended recipient, or the employee or agent responsible for delivering it to the intended recipient, you are hereby notified that reading it is strictly prohibited. If you have received this e-mail in error, please immediately return it to the sender and delete it from your system. Thank you.
