AVR genes

[Peter]

Is anyone familiar with the particulars of avr genes?  I have isolated and 
sequenced a gene in Erwinia amylovora which I think may be an avr gene 
because there is an avr gene in the same place in the pseudomonas syringea 
genome and the two bacterial genomes are homologous and colinear.  However, I 
am not entirely sure what goes into being an avirulane gene.  The other people 
in my lab (I'm just a puny undergraduate) give me general sweeping comments 
regarding host-specificity.  Can anyone tell me how I would go about 
determining whether what I have is trully an avr gene?

my email address is pk20 at cornell.edu.  I would appreciate any information on 
this subject.

thank you,

Peter Kolchinsky