Answer:


First the hints... Q is your Query sequence, S is the database Searched one...
This is a chymotrypsin. It is 83 % identical. From BLAST you click your way to SwissProt to find: 

  SIGNAL        1     18
  CHAIN        19    263       CHYMOTRYPSINOGEN B.
  CHAIN        19     31       CHYMOTRYPSIN B, A CHAIN.
  CHAIN        34    164       CHYMOTRYPSIN B, B CHAIN.
  CHAIN       167    263       CHYMOTRYPSIN B, C CHAIN.
  ACT_SITE     75     75       CHARGE RELAY SYSTEM (BY SIMILARITY). His
  ACT_SITE    120    120       CHARGE RELAY SYSTEM (BY SIMILARITY). Asp
  ACT_SITE    213    213       CHARGE RELAY SYSTEM (BY SIMILARITY). Ser
  DISULFID     19    140       BY SIMILARITY.
  DISULFID     60     76       BY SIMILARITY.
  DISULFID    154    219       BY SIMILARITY.
  DISULFID    186    200       BY SIMILARITY.
  DISULFID    209    238       BY SIMILARITY.

But be aware, due to the insertion of two residues, the active site residues do not all have the same residue numbers as in this database hit, because there is a gap of two aa between the second and third active side residue, somewhere. You would like them to make an alignment with CLUSTAL in which they can see this immediately (they can also see it in the BLAST output). The three residues and the gap that causes the number shift for the third one are indicated with an o underneath; the active site residues with an A. 

funnyprotease      MAFIWLLSCYALLGTTFGCGVNAIHPVLTGLSKIVNGEEAVPGTWPWQVTLQDRSGFHFC
CTRB_HUMAN         MAFLWLLSCWALLGTTFGCGVPAIHPVLSGLSRIVNGEDAVPGSWPWQVSLQDKTGFHFC
Id                 ***:*****:*********** ******:***:*****:****:*****:***::*****
 
funnyprotease      GGSLISEDWVVTAAHCGVRTSEILIAGEFDQGSDEDNIQVLRIAKVFKQPKYSILTVNND
CTRB_HUMAN         GGSLISEDWVVTAAHCGVRTSDVVVAGEFDQGSDEENIQVLKIAKVFKNPKFSILTVNND
Id                 **************A******::::**********:*****:******:**:*******A
 
funnyprotease      ITLLKLASPARYSQTISAVCLPSVDDD--AGSLCATTGWGRTKYNANKSPDKLERAALPL
CTRB_HUMAN         ITLLKLATPARFSQTVSAVCLPSADDDFPAGTLCATTGWGKTKYNANKTPDKLQQAALPL
Id                 *******:***:***:*******.***oo**:********:*******:****::*****
 
funnyprotease      LTNAECKRSWGRRLTDVMICGAASGVSSCMGDSGGPLVCQKDGAYTLVAIVSWASDTCSA
CTRB_HUMAN         LSNAECKKSWGRRITDVMICAGASGVSSCMGDSGGPLVCQKDGAWTLVGIVSWGSDTCST
Id                 *:*****:*****:******..**********A***********:***.****.*****:
 
funnyprotease      SSGGVYAKVTKIIPWVQKILSSN
CTRB_HUMAN         SSPGVYARVTKLIPWVQKILAAN
Id                 ** ****:***:********::*

The numbers are 75, 120 and 211 (corresponding to 213, but shifted two positions by the gap)